OF MAKING, AND USES THEREOF

FIELD OF THE INVENTION

[0001 ] The present invention relates to crystalline (thio)nicotinamide ribofuranoside salts, methods of making such crystalline salts, a pharmaceutical composition comprising same, and use of said crystalline salts as nutritional (dietary) supplements. Furthermore, the present invention relates to a composition comprising amorphous (thio)nicotinamide ribofuranoside salts and its use as nutritional (dietary) supplement.

[0002] Furthermore, the present invention relates to a composition comprising (thio)nicotinamide ribofuranoside in amorphous form, a method of making same, and uses thereof as nutritional supplement or pharmaceutical composition.

BACKGROUND OF THE INVENTION

[0003] Nicotinamide riboside (nicotinamide-3-D-ribofuranoside; CAS Number 1341 - 23-7) is a precursor of nicotinamide adenine dinucleotide (NAD7NADH) and nicotinamide adenine dinucleotide phosphate (NADP7NADPH). In addition, nicotinamide riboside is a niacin (vitamin B3) equivalent. Nicotinamide riboside may be used in pharmaceutical compositions and nutritional supplements or as an intermediate product in the chemical synthesis of NAD(H) or NADP(H).

[0004] WO 2016/014927 discloses a crystalline form of nicotinamide riboside chloride which is described to have advantageous properties relative to amorphous forms, e.g. since it may be better purified compared to amorphous forms. The crystalline chloride salt is obtained from an amorphous chloride salt by re-crystallization in a polar solvent such as methanol.

[0005] Lee et al. (Chem. Commun., 1999, 729-730) disclose chemical synthesis of b- nicotinamide riboside bromide. The synthesis comprises conversion of tetraacetyl-3-D- ribofuranose to a 1.5:1 b:a mixture of sugar bromide intermediate compounds using hydrogen bromide in CH2CI2 as bromination agent. Reaction of the sugar bromide intermediate compounds with nicotinamide in SO2 at -10 °C followed by crystallization from 5:1 acetone-Bu'OMe allegedly afforded acetylated nicotinamide riboside (b:a = 25:1 ) in 90 % yield.

[0006] According to an alternative approach described in Lee et al., a 3.3:1 (b:a) anomeric mixture was obtained when acetonitrile was used instead of S0 ₂ in the glycosylation step, and the pure b-anomer of acetylated nicotinamide riboside was allegedly selectively crystallized in 65 % yield from the reaction mixture (-15 °C). Furthermore, deacetylation (i.e. deprotection) with ammonia in methanol followed by crystallization is reported to give crystalline b-nicotinamide bromide salt in 80 % isolated yield.

[0007] Despite these efforts in the art, the conventional manufacturing methods of nicotinamide riboside are costly, not suited for nicotinamide riboside production on an industrial scale, and/or do not yield the required product quality, in particular in terms of product purity.

OBJECTS OF THE INVENTION

[0008] In view of the above, there is a need in the art for b-nicotinamide riboside salts of high purity which can be prepared at low costs and on an industrial scale.

SUMMARY OF THE INVENTION

[0009] The present inventors unexpectedly found that the process of producing b- (thio)nicotinamide ribofuranoside can be improved, e.g. by using appropriate bromination agents, deprotecting agents, and/or specific reaction conditions such as purification/crystallization conditions, resulting in a cost-efficient production of crystalline bromide or chloride salts of b-(ίIiίo)hίooίίh3ΐti^b ribofuranoside compounds as well as further salts of pharmaceutically acceptable anions like sulfate and phosphate with high purity and in high yields on an industrial scale.

[0010] According to a first aspect, the present invention relates to a method of making crystalline nicotinamide^-D-ribofuranoside bromide of formula O-la

O-la or crystalline thionicotinamide-3-D-ribofuranoside bromide of formula S-la

Br

S-la comprising at least step (A):

(A) subjecting a tetra-0-acyl-3-D-ribofuranose of formula wherein each R is independently selected from acyl and wherein each R is preferably acetyl, to hydrogen bromide in acetic acid to yield a tri-0-acyl-3-D-ribofuranoside bromide of formula III

III. [001 1 ] The method of the present invention may further comprise the following step

(B):

(B) reacting the compound of formula III with nicotinamide of formula O-IV

to obtain a nicotinamide-2, 3, 5-tri-0-acyl-3-D-ribofuranoside bromide of formula O-Va:

or reacting the compound of formula III with thionicotinamide of formula S-IV

to obtain a thionicotinamide-2,3,5-triacyl-3-D-ribofuranoside bromide of formula S-Va:

S-Va.

[0012] Furthermore, the method of the present invention may comprise the following step (D):

(D) deprotecting the compound of formula O-Va or formula S-Va obtained in step (B), or obtained in optional step (C) of purifying the compound of formula O-Va or formula S-Va obtained in step (B), by removing the R groups using hydrogen bromide in acetic acid to give the compound of formula O-la or formula S-la.

[0013] According to a second aspect, the present invention relates to a method of making a crystalline nicotinamide-3-D-ribofuranoside salt or a crystalline thionicotinamide-3-D-ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion, particularly chloride, sulfate and phosphate, the method comprising:

(I) making a crystalline nicotinamide-3-D-ribofuranoside bromide of formula O-la or a crystalline thionicotinamide-3-D-ribofuranoside bromide of formula S-la according to a method of the first aspect; and subsequently subjecting the nicotinamide-3-D-ribofuranoside bromide of formula O-la or the thionicotinamide-3-D-ribofuranoside bromide of formula S-la to ion exchange using an ion exchanger loaded with said pharmaceutically acceptable anion; or

(II) making a crystalline nicotinamide-2, 3, 5-tri-0-acyl-3-D-ribofuranoside bromide of formula O-Va or a crystalline thionicotinamide-2,3,5-tri-0-acyl-3-D- ribofuranoside bromide of formula S-Va according to a method as described herein (e.g. step (B), or step (B) and step (A), or step (B) and step (A) and step (C), of the method of the first aspect), and deprotecting the compound of formula O-Va or formula S-Va in the presence of a pharmaceutically acceptable anion and protons; and subsequently subjecting the formed product to ion exchange using an ion exchanger loaded with said pharmaceutically acceptable anion; or

(III) making a crystalline nicotinamide-2, 3, 5-tri-0-acyl-3-D-ribofuranoside bromide of formula O-Va or a crystalline thionicotinamide-2,3,5-tri-0-acyl-3-D- ribofuranoside bromide of formula S-Va according to a method as described herein (e.g. step (B), or step (B) and step (A), or step (B) and step (A) and step (C), of the method of the first aspect), and subjecting the compound of formula O-Va or formula S-Va to ion-exchange with a pharmaceutically acceptable anion using an ion exchanger loaded with said pharmaceutically acceptable anion; and subsequently deprotecting the formed ion exchanged product in the presence of protons and said pharmaceutically acceptable anion.

[0014] According to a third aspect, the present invention relates to a crystalline nicotinamide-2, 3, 5-tri-0-acetyl-3-D-ribofuranoside bromide of formula O-Va, wherein R is acetyl, characterized by a powder X-ray diffraction pattern as defined in Fig. 1 herein below; or a crystalline nicotinamide-3-D-ribofuranoside bromide of formula O-la characterized by a powder X-ray diffraction pattern as defined in Fig. 2 herein below; or a crystalline nicotinamide-2, 3, 5-tri-0-acetyl^-D-ribofuranoside chloride of formula O-Vb, wherein R is acetyl, characterized by a powder X-ray diffraction pattern as defined in Fig. 3 herein below; or a crystalline nicotinamide-3-D-ribofuranoside chloride of formula O-lb characterized by a powder X-ray diffraction pattern as defined in Fig. 4 herein below; or a crystalline thionicotinamide-2,3,5-tri-0-acetyl^-D-ribofuranoside bromide of formula S- Va, wherein R is acetyl, characterized by a powder X-ray diffraction pattern as defined in Fig. 5 herein below; or a crystalline thionicotinamide-3-D-ribofuranoside bromide of formula S-la characterized by a powder X-ray diffraction pattern as defined in Fig. 6 herein below; or a crystalline thionicotinamide-3-D-ribofuranoside chloride of formula S- Ib characterized by a powder X-ray diffraction pattern as defined in Fig. 7 herein below; or a crystalline thionicotinamide-2,3,5-tri-0-acetyl-3-D-ribofuranoside chloride of formula S-Vb characterized by a powder X-ray diffraction pattern as defined in Fig. 8 herein below. [0015] The third aspect of the present invention further relates to a crystalline nicotinamide-3-D-ribofuranoside bromide of formula O-la or a crystalline thionicotinamide-3-D-ribofuranoside bromide of formula S-la, obtainable by a method of the first aspect; or a crystalline nicotinamide-3-D-ribofuranoside salt or a crystalline thionicotinamide-3-D-ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion (i.e. not bromide), such as chloride, sulfate and phosphate, obtainable by a method of the second aspect.

[0016] According to a fourth aspect, the present invention relates to the use of a crystalline nicotinamide-3-D-ribofuranoside salt or a crystalline thionicotinamide-3-D- ribofuranoside salt of the third aspect as nutritional supplement. Furthermore, the fourth aspect also relates to a pharmaceutical composition comprising said crystalline nicotinamide-3-D-ribofuranoside salt or said crystalline thionicotinamide-3-D- ribofuranoside salt.

[0017] According to a fifth aspect, the present invention relates to a method of making a composition comprising an amorphous nicotinamide-3-D-ribofuranoside salt or an amorphous thionicotinamide-3-D-ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion, particularly chloride, sulfate and phosphate, and a carrier, the method comprising making a crystalline nicotinamide-3-D-ribofuranoside salt or a crystalline thionicotinamide-3-D-ribofuranoside salt according to a method of the second aspect, and further comprising step (F), and optionally step (G):

(F) contacting the salt with a carrier, e.g. pullulan, and one or more solvents;

(G) removing the one or more solvents from the mixture obtained in step (F) to obtain a solid form of the composition in which the nicotinamide-3-D-ribofuranoside salt or thionicotinamide-3-D-ribofuranoside salt is present in amorphous form.

[0018] According to a sixth aspect, the present invention relates to a composition comprising a nicotinamide-3-D-ribofuranoside salt or a thionicotinamide-3-D- ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion, particularly chloride, sulfate and phosphate, and a carrier, wherein said nicotinamide-b- D-ribofuranoside salt and said thionicotinamide-3-D-ribofuranoside salt are amorphous. Preferably, the composition is prepared by a method according to the fifth aspect. [0019] The composition according to the sixth aspect may be used for the same applications or uses as defined in the fourth aspect, i.e. as nutritional supplement or as pharmaceutical ingredient, e.g. in a pharmaceutical composition that optionally comprises a carrier such as pullulan.

[0020] According to a seventh aspect, the present invention relates to a method of making a tri-0-acyl-3-D-ribofuranoside bromide of formula III

the method comprising step (a):

(a) subjecting a tetra-0-acyl-3-D-ribofuranoside of formula II

wherein each R is independently selected from acyl and wherein each R is preferably acetyl, to hydrogen bromide in acetic acid.

[0021 ] According to an eighth aspect, the present invention relates to a method of removing acyl groups, in particular acetyl groups, from a nicotinamide-2, 3, 5-tri-0-acyl-3- D-ribofuranoside bromide of formula O-Va or a nicotinamide-2, 3, 5-tri-0-acyl-3-D- ribofuranoside chloride of formula O-Vb

O-Va or O-Vb; or from a thionicotinamide-2,3,5-tri-0-acyl-3-D-ribofuranoside bromide of formula S-Va or a thionicotinamide-2,3,5-tri-0-acyl-3-D-ribofuranoside chloride of formula S-Vb

Br or Cl

S-Va or S-Vb; wherein each R is independently selected from acyl and wherein each R is preferably acyl, the method comprising at least step (i) or (ii):

(i) reacting the compound of formula O-Va or formula S-Va with hydrogen bromide in acetic acid;

(ii) reacting the compound of formula O-Va or formula S-Va with hydrogen chloride in methanol.

[0022] Further embodiments are set forth in the appended claims.

BRIEF DESCRIPTION OF THE FIGURES

[0023] The present invention is further described by the appended figures, in which: Fig. 1 shows a powder X-ray pattern of crystalline nicotinamide-2, 3, 5-tri-0-acetyl-3-D- ribofuranoside bromide of formula O-Va (R = acetyl);

Fig. 2 shows a powder X-ray pattern of crystalline nicotinamide^-D-ribofuranoside bromide of formula O-la;

Fig. 3 shows a powder X-ray pattern of crystalline nicotinamide-2, 3, 5-tri-0-acetyl-3-D- ribofuranoside chloride of formula O-Vb (R = acetyl);

Fig. 4 shows a powder X-ray pattern of crystalline nicotinamide^-D-ribofuranoside chloride of formula O-lb;

Fig. 5 shows a powder X-ray pattern of crystalline thionicotinamide-2,3,5-tri-0-acetyl- b-D-ribofuranoside bromide of formula S-Va (R = acetyl);

Fig. 6 shows a powder X-ray pattern of crystalline thionicotinamide^-D- ribofuranoside bromide of formula S-la;

Fig. 7 shows a powder X-ray pattern of crystalline thionicotinamide^-D- ribofuranoside chloride of formula S-lb;

Fig. 8 shows a powder X-ray pattern of crystalline thionicotinamide-2,3,5-tri-0-acetyl b-D-ribofuranoside chloride of formula S-Vb (R = acetyl); and

Fig. 9 shows a powder X-ray pattern of amorphous pullulan-supported nicotinamide- b-D-ribofuranoside chloride;

{x-axis: Position [°2Theta] (Copper(Cu); y-axis: Counts), respectively}.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The various aspects of the present invention will now be described in more detail with reference to the figures.

Method of making crystalline (thio)nicotinamide- -D-ribofuranoside bromide O-la or S-la (first aspect)

[0025] According to a first aspect, the invention relates to a method of making crystalline nicotinamide-3-D-ribofuranoside bromide of formula O-la

O-la; or a crystalline thionicotinamide-3-D-ribofuranoside bromide of formula S-la

Br

S-la. [0026] As used herein, the term “(thio)nicotinamide” encompasses the term “nicotinamide” and “thionicotinamide” such as nicotinamide-3-D-ribofuranoside and thionicotinamide-3-D-ribofuranoside.

[0027] The method according to the invention comprises at least step (A):

(A) subjecting a tetra-0-acyl-3-D-ribofuranose of formula II,

wherein each R is independently an acyl group, to hydrogen bromide in acetic acid to yield a tri-0-acyl-3-D-ribofuranoside of formula III:

[0028] The term “acy/” as synonymously used with the term “acyl group” in the compound of formula II means that the acyl group may be independently selected from alkyl carbonyl, aryl carbonyl or heteroaryl carbonyl.

[0029] The term“alkyl carbonyi’ is synonymously used with the term“alkanoyr.

[0030] In one embodiment, R is independently selected from alkyl carbonyl, aryl carbonyl and heteroaryl carbonyl, preferably from C-MO alkyl carbonyl and benzoyl, and is preferably acetyl.

[0031 ] In one embodiment, acyl may be substituted. [0032] In one embodiment, acyl may be independently substituted with one or more of the following substituents: C-i- ₆ alkyl, C-i- ₆ alkoxy, C-i- ₆ thioalkyl, halogen, nitro, cyano, NH(C _1-6 alkyl), N(C _1-6 alkyl) ₂ , and S0 ₂ N(C _1-6 alkyl) ₂ .

[0033] In one embodiment, acyl is Ci _-6 alkanoyl such as formyl, acetyl, propionyl, butyryl, valeryl or cyclohexyl, optionally substituted with one or more of the substituents mentioned above.

[0034] In another embodiment, acyl is benzoyl or naphthoyl, preferably benzoyl, optionally substituted with one or more of the substituents mentioned above.

[0035] Tetra-0-acyl-3-D-ribofuranoses of formula II are either known compounds or may be prepared according to known methods.

[0036] In a preferred embodiment, commercially available tetra-0-acetyl-3-D- ribofuranose (CAS Number 13035-61 -5)

is used in step (A).

[0037] Thus, R is preferably acetyl.

[0038] Hydrogen bromide in acetic acid, preferably glacial acetic acid, as used in step (A) is commercially available. A preferred composition comprises 33 % by weight of hydrogen bromide in glacial acetic acid (CAS Number 37348-16-6).

[0039] Preferably, the reaction is carried out in an aprotic polar solvent, preferably a nitrile. In a preferred embodiment, acetonitrile is used as solvent in which the compound of formula II is dissolved or suspended prior to the addition of hydrogen bromide in acetic acid. [0040] The reaction temperature is advantageously kept in a temperature range of from -10 to 10 °C such as -5 to 5 °C in order to control the slightly exothermic reaction of compound II with hydrogen bromide in acetic acid.

[0041 ] The compound of formula III may be isolated from the reaction mixture by evaporating the solvent and acetic acid.

[0042] However, the inventors of the present invention discovered that an evaporation of solvent and acetic acid on an industrial scale in commonly used reactors may significantly negatively affect the properties of the resulting tri-0-acyl-3-D-ribofuranoside bromide of formula III in terms of yield due to degradation and side-reactions such as epimerization or ring opening.

[0043] Furthermore, the subsequent reaction in step (B) with nicotinamide of formula O-IV or thionicotinamide of formula S-IV (nicotinamide O-IV, CAS Number 98-92-0; thionicotinamide S-IV, CAS Number 4621 -66-3) to the desired crystalline nicotinamide- 2, 3, 5-tri-0-acyl-3-D-ribofuranoside bromide of formula O-Va or thionicotinamide-2,3,5-tri- 0-acyl-3-D-ribofuranoside bromide of formula S-Va as defined below is severely hampered, respectively the isolation of a crystalline product is not possible at all.

[0044] Therefore, the inventors investigated whether the crude product obtained in step (A), i.e. a product containing tri-0-acyl-3-D-ribofuranoside bromide of formula III, acetic acid and hydrogen bromide, may be reacted with (thio)nicotinamide IV in the subsequent step (B). It was expected that due to the reduced nucleophilicity of (thio)nicotinamide IV as a consequence of salt formation of (thio)nicotinamide IV with acetic acid the substitution of bromide in tri-0-acyl-3-D-ribofuranoside bromide of formula III by nicotinamide of formula O-IV or thionicotinamide of formula S-IV would be hampered or even fail.

[0045] The inventors of the present invention discovered that - contrary to expectation - the reaction mixture obtained in step (A) may be used for substituting bromide in tri-O- acyl-P-D-ribofuranoside bromide of formula III in good yield by (thio)nicotinamide IV. This was unexpected and thus surprising.

[0046] Without being bound by theory, it is believed that the reduced nucleophilicity of (thio)nicotinamide of formula IV upon acetate formation due to the presence of acetic acid in step (B), when the crude product obtained in step (A) is used for substituting bromide in tri-0-acyl-3-D-ribofuranoside bromide of formula III, is still sufficient in order to effect substitution: It further contributes to a smooth reaction with tri-0-acyl-3-D- ribofuranoside bromide of formula III such that side-reactions, e.g. ring opening reactions, epimerization or degradation reactions, are avoided as far as possible. This promotes the formation of a crystallized acylated product of formula Va, i.e. nicotinamide- 2, 3, 5-tri-0-acyl-3-D-riboside bromide of formula O-Va or thionicotinamide-2,3,5-tri-0- acyl-3-D-riboside bromide of formula S-Va.

[0047] This unexpected finding has been proven to be of crucial importance for a successful up-scaling of the reaction to an industrial scale.

[0048] Therefore, in a preferred embodiment, the compound of formula III formed in step (A) is not isolated, but is employed in the next step (B) of the method according to the invention as the crude product, i.e. is used as the product which is contained in the reaction mixture obtained in step (A).

[0049] Thus, in one embodiment, the next step (B) in the method according to the invention is carried out using (thio)nicotinamide IV in form of its acetate.

[0050] In another embodiment, preferably the crude reaction mixture obtained in step (A) is used comprising the (thio)nicotinamide and acetic acid, respectively a composition comprising at least a portion of the reaction mixture obtained in step (A).

[0051 ] Accordingly, the method further comprises the following step (B):

(B) reacting a tri-0-acyl-3-D-ribofuranoside bromide of formula III with nicotinamide of formula O-IV

O-IV, respectively with thionicotinamide of formula S-IV

S-IV, to yield a nicotinamide-2, 3, 5-tri-0-acyl-3-D-ribofuranoside bromide of formula O-Va:

O-Va, respectively a thionicotinamide-2,3,5-tri-0-acyl-3-D-riboside bromide of formula S-

Va

S-Va.

[0052] In a preferred embodiment, nicotinamide O-IV, respectively thionicotinamide S- IV, is used in an excess compared to tri-0-acyl-3-D-ribofuranoside bromide of formula III.

[0053] Furthermore, and advantageously, nicotinamide of formula O-IV, respectively thionicotinamide of formula S-IV, is used in an amount sufficient - due to its basic properties - to neutralize an excess of hydrogen bromide and acetic acid still contained in the reaction mixture formed in step (A). The resulting salts (thio)nicotinamide bromide and/or acetate precipitate from the reaction mixture and may simply be separated off by filtration.

[0054] The resulting filtrate contains intermediate (thio)nicotinamide-2,3,5-tri-0-acyl-3- D-ribofuranoside bromide of formula Va, and only a comparatively small amount of (thio)nicotinamide IV if the excess of (thio)nicotinamide IV is chosen appropriately.

[0055] Since the compound of formula III is provided in the form of a mixture of anomers, also (thio)nicotinamide-2,3,5-tri-0-acyl-3-D-ribofuranoside bromide of formula Va is formed as a mixture of anomers.

[0056] The intermediate compound of formula Va is typically produced as a mixture of anomers b:a in a ratio of from about 5:1 to 6:1. This is an improvement over the method disclosed in the Lee-reference discussed above, where the similar reaction provided for a less favorable ratio of 3.3:1 of a b:a mixture of anomeric nicotinamide-2, 3, 5-tri-O-acyl- b-D-ribofuranoside bromides.

[0057] This favorable ratio of b:a anomer in the intermediate compound of formula V hypothesizes that also tri-O-acyl^-D-ribofuranoside bromide of formula III is typically produced as a mixture of anomers b:a in a ratio range from about 5:1 to 6:1. This would be an additional improvement over the method disclosed in the Lee-reference discussed above, where the analogous reaction using hydrogen bromide in dichloromethane for making tri-O-acyl^-D-ribofuranoside bromide of formula III provided for a less favorable ratio of 1.5:1 in terms of a b:a mixture of anomeric sugar bromides.

[0058] The inventors discovered that a successful large-scale reaction is possible only under the specific conditions indicated below.

[0059] In particular, the inventors discovered that besides the use of (thio)nicotinamide acetate for the substitution of bromide in tri-O-acyl^-D-ribofuranoside bromide of formula III, also the use of an excess of nicotinamide of formula O-IV or thionicotinamide of formula S-IV adapted to the amount of hydrogen bromide used in the bromination step (A), is of crucial importance for carrying out the reaction in the large scale. [0060] Since hydrogen bromide is used in a slight molar excess in the bromination reaction in step (A) relative to acyl compound of formula II (approx. 1.2 mole hydrogen bromide to 1 mole of compound of formula II), also (thio)nicotinamide of formula IV should be used in an appropriate excess in step (B) in order to neutralize said hydrogen bromide still being contained in the reaction mixture since said hydrogen bromide otherwise would negatively affect glycosylation. This may be seen in a reduced yield of the compound of formula Va if the reaction is carried out in absence of an excess of (thio)nicotinamide of formula IV.

[0061 ] Furthermore, surprisingly, the filtrate contains despite said excess of (thio)nicotinamide of formula IV only small amounts thereof, which facilitates the spontaneous crystallization of the substantially pure compound of formula O-Va, respectively S-Va, from acetone.

[0062] Accordingly, in a preferred embodiment, the molar ratio of hydrogen bromide to acyl compound of formula II used in step (A) is selected such to range from 1.1 :1 to 1.3:1 , wherein the molar ratio of (thio)nicotinamide of formula IV used in step (B) to hydrogen bromide used in step (A) is in the range of from 1.05:1 to 1.2:1.

[0063] In a further preferred embodiment, the molar ratio of hydrogen bromide to acyl compound of formula II used in step (A) is selected such to range from 1.15:1 to 1.25:1 , wherein the molar ratio of (thio)nicotinamide of formula IV used in step (B) to hydrogen bromide used in step (A) is in the range of from 1.1 :1 to 1.15:1.

[0064] Furthermore, it is advantageous to carry out step (B) such that a heated solution of (thio)nicotinamide of formula IV in acetonitrile is added to a cooled solution comprising tri-0-acyl-3-D-ribofuranoside bromide of formula III and a solvent, preferably acetonitrile.

[0065] Without being bound by theory, it is believed that under said conditions glycosylation is advantageously faster that the competing degradation of tri-0-acyl-3-D- ribofuranoside bromide of formula III.

[0066] Accordingly, in a preferred embodiment, step (B) is carried out such that (thio)nicotinamide of formula IV dissolved in acetonitrile is added to a solution comprising tri-0-acyl-3-D-ribofuranoside bromide of formula III and acetonitrile, hydrogen bromide and acetic acid, wherein the temperature of the solution of (thio)nicotinamide of formula IV in acetonitrile is kept in a range of from 50 °C to 75 °C, and the temperature of the solution comprising tri-0-acyl-3-D-ribofuranoside bromide of formula III is kept in a temperature range of from -10 °C to 30 °C.

[0067] In a preferred embodiment, the temperature of the solution of (thio)nicotinamide of formula IV in acetonitrile is kept in a range of from 70 °C to 75 °C and the temperature of the solution comprising tri-0-acyl-3-D-ribofuranoside bromide of formula III is kept in a temperature range of from 0 °C to 20 °C.

[0068] After filtering the precipitated (thio)nicotinamide hydrobromide, respectively acetate, and after evaporating the solvent, preferably acetonitrile, the compound of formula Va (O-Va or S-Va) may be isolated.

[0069] Although the crude product may be employed in the next step, it is advantageous to purify and crystallize the compound of formula Va. Using a purified and crystallized compound of formula Va in the deprotecting step of the method according to the invention, i.e. step (D), improves the tendency of the target compound of formula la, either O-la or S-la, to result in a crystallized and thus in a substantially pure form.

[0070] Preferably, the compound of formula Va may be re-crystallized from acetone. The pure b-anomer is obtained.

[0071 ] Accordingly, in one embodiment, the method further comprises step (C):

(C) purifying the product obtained in step (B).

[0072] Preferably, purification according to step (C) is crystallization or re crystallization.

[0073] The yield over steps (B) and (C) is typically in the range of from 40 to 50 %.

[0074] In the next step of the method according to the invention, the acyl groups in the product obtained in step (B) or (C) are cleaved, i.e. the protected hydroxyl groups are deprotected. [0075] Basically any method known in the art may be used to remove the acyl groups from the protected OH-groups.

[0076] In one embodiment, ammonia such as ammonia in methanol may be used for deprotection as disclosed in the above-discussed Lee reference. The inventors of the present invention can confirm the respective disclosure in said Lee-reference that this method cannot easily be repeated on a large scale and that the extent of cleavage may largely depend on the initial concentration and the total amount of ammonia in the reaction mixture. Moreover, unfavorable epimerization and degradation products resulting in brownish products may be observed which may negatively affect the formation of the target compound of formula la, either of formula O-la or of formula S-la, in crystallized form.

[0077] The inventors of the present invention discovered that cleavage may be advantageously performed with hydrogen bromide in acetic acid without the addressed drawbacks.

[0078] The reaction may be carried out in the presence of a solvent. A preferred solvent is methanol.

[0079] Accordingly, the method further comprises step (D):

(D) deprotecting the compound of formula Va, i.e. either of formula O-Va or of formula S-Va, obtained in step (B) or (C) by removing the R groups using hydrogen bromide in acetic acid to give the compound of formula la, i.e. either of formula O-la or of formula S-la.

[0080] This reaction may be beneficially carried out also at a large scale.

[0081 ] Since the deprotection reaction is slightly exothermic, it is preferred to control the reaction temperature. In a preferred embodiment, the temperature is kept in a range of from -5 °C to 25 °C such as 0 °C to 20 °C.

[0082] In one embodiment, after cleavage of the acyl groups, i.e. the deprotection step, acetic acid and formed acids stemming from the acyl residues may be distilled off in vacuum, if desired. [0083] The formed target compound of formula O-la or of formula S-la frequently directly precipitates from the solution obtained in the deprotection step in the form of crystals.

[0084] If necessary, crystallization may be promoted by the addition of seeding crystals.

[0085] The crystallized product O-la or S-la may be obtained in a purity of more than 97 %, i.e. nearly free from the a-anomer, and containing only minor amounts of (thio)nicotinamide of formula IV which has been used for substituting bromide in tri-O- acyl-P-D-ribofuranoside bromide of formula III, respectively for neutralizing an excess of hydrogen bromide.

[0086] If further necessary, compound of formula O-la or of formula S-la may be further purified, preferably by re-crystallization. A suitable solvent is e.g. methanol.

[0087] In a preferred embodiment, the method further comprises step (E):

(E) purifying the product obtained in step (D).

[0088] In a preferred embodiment, purification according to step (E) comprises or is crystallization or re-crystallization.

[0089] The yield over steps (D) and (E) is typically in the range of from 60 to 70 %.

[0090] The compound of formula la (O-la or S-la) may be transferred to the chloride lb (O-lb or S-lb), if desired, since the chloride typically is pharmaceutically more acceptable than the bromide.

[0091 ] Advantageously, other crystalline salts in which the anion is a pharmaceutically acceptable anion may be prepared starting from the bromide of formula la. Preferably, sulfates and phosphates may be prepared.

Method of making a crystalline (thio)nicotinamide- -D-ribofuranoside chloride or another pharmaceutically acceptable salt (second aspect) [0092] According to a second aspect, the invention relates to a method of making a crystalline nicotinamide-3-D-ribofuranoside salt or a crystalline thionicotinamide-3-D- ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion such as chloride or any other pharmaceutically acceptable anion, starting from (a deprotected) product of formula la (O-la or S-la) or (a protected) product Va (O-Va or S- Va) as defined in the first aspect.

[0093] The target compounds may be prepared by at least three embodiments, i.e. either by

- exchanging the bromide ion in a compound of formula O-la or S-la via ion- exchange with a pharmaceutically acceptable anion such as chloride (embodiment 1 ); or

- deprotecting, i.e. cleaving the acyl groups in a compound of formula O-Va or S- Va in the presence of a pharmaceutically acceptable anion and protons such as hydrogen chloride, and subsequently subjecting the formed product to ion exchange with the respective pharmaceutically acceptable anion such as chloride (embodiment 2); or

- subjecting a compound of formula O-Va or S-Va to ion-exchange with a pharmaceutically acceptable anion such as chloride and subsequently deprotecting the formed ion-exchanged product with the respective acid of said pharmaceutically acceptable anion such as hydrogen chloride (embodiment 3).

[0094] These embodiments are discussed in the following in more detail.

Embodiment 1 : Exchanging bromide with chloride or another pharmaceutically acceptable anion

[0095] According to a specific embodiment, the invention relates to a method of making a crystalline nicotinamide-3-D-ribofuranoside chloride of formula O-lb or a crystalline thionicotinamide-3-D-ribofuranoside chloride of formula S-lb. [0096] This method encompasses a method in which the product of formula O-la or S- la formed in the method according to the first aspect is subjected to ion exchange using an ion exchanger loaded with chloride ions.

[0097] Accordingly, in one embodiment, the invention comprises a method of making a crystalline nicotinamide-3-D-ribofuranoside chloride of formula O-lb

O-lb, or a crystalline thionicotinamide-3-D-ribofuranoside chloride of formula S-lb

comprising step (b):

(b) subjecting the crystalline compound of formula O-la or S-la as defined in the first aspect [step (a)] to ion exchange using an ion exchanger loaded with chloride ions.

[0098] Suitable ion exchangers are known from the state of the art: The ion exchange may be performed by the commonly known methods.

[0099] The inventors further discovered that the method of converting the bromide of formula O-la or S-la to the chloride of formula O-lb or S-lb by ion exchange may be transferred to anions being different from chloride, but which may also be loaded to an ion-exchanger.

[00100] Basically, any anion may be used for ion exchange which is considered in the art as a pharmaceutically acceptable anion.

[00101 ] In a preferred embodiment, said anion is selected from an inorganic acid, preferably hydrogen sulfate, sulfate, dihydrogen phosphate, hydrogen phosphate, or phosphate.

[00102] Anions of organic acids may also be used. Suitable anions are preferably the anions of fumaric acid, maleic acid, succinic acid, citric acid, tartaric acid, acetic acid, and methane sulfonic acid.

[00103] Accordingly, the method according to the invention encompasses a method in which the product of formula O-la or S-la formed in the method according to the first aspect is subjected to ion exchange using an ion exchanger loaded with anions such as hydrogen sulfate or sulfate, preferably hydrogen sulfate, or dihydrogen phosphate, hydrogen phosphate, or phosphate, preferably dihydrogen phosphate, or fumaric acid, maleic acid, succinic acid, citric acid, tartaric acid, acetic acid and methane sulfonic acid.

[00104] Thus, in a further preferred embodiment, the invention relates to a method of making a crystalline (thio)nicotinamide-3-D-ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion, comprising step (bb):

(bb) subjecting the crystalline compound of formula O-la or S-la as defined in the first aspect to ion exchange using an ion exchanger loaded with a pharmaceutically acceptable anion.

[00105] The ion-exchange may be performed according to known methods. The exchange may be performed in water and/or organic solvents, depending on the solubility of the used starting material.

Embodiment 2: Deprotectinq the compound of formula O-Va or S-Va in the presence of chloride or another pharmaceutically acceptable anion, followed by ion exchange [00106] In another specific embodiment, at least a portion of the product formed in the cleavage according to step (D) as defined in the first aspect may be converted to the chloride, if the cleavage of the acyl groups, i.e. the deprotecting step, is performed in the presence of chloride ions.

[00107] In a preferred embodiment, the chloride ions stem from hydrogen chloride, i.e. cleavage is performed in the presence of hydrogen chloride, preferably hydrogen chloride in methanol. Then commonly a mixed salt is obtained, e.g. a mixture of bromide to chloride salt, e.g. in the range of from 20:80 to 30:70.

[00108] The mixed salt may then be subjected to an ion exchanger loaded with chloride ions in order to make the pure chloride of formula lb.

[00109] However, depending on the load with chloride ions, mixtures of a bromide of formula la and chloride of formula lb may be also prepared, if desired.

[001 10] Likewise, it is also possible to convert at least a portion of the product formed in the cleavage according to step (D) as defined in the first aspect to a pharmaceutically acceptable anion different from chloride as disclosed above, if the cleavage is performed in the presence of said pharmaceutically acceptable anion.

[001 1 1 ] In a preferred embodiment, the pharmaceutically acceptable anion stems from the respective acid, i.e. cleavage is performed in the presence of the respective acid, preferably the acid in methanol. Then usually a mixed salt is obtained, e.g. a mixture of bromide with the pharmaceutically acceptable anion.

[001 12] The mixed salt may then be subjected to an ion exchanger loaded with the pharmaceutically acceptable anion in order to make the pure respective salt, if desired.

[001 13] Thus, in a specific embodiment, the method comprises prior to step (b) step (c):

(c) deprotecting the compound of formula O-Va or S-Va obtained in step (B) or (C) as defined in the first aspect by removing the R groups, i.e. the acyl protecting groups, using hydrogen bromide in acetic acid in the presence of chloride ions.

[001 14] In a more general embodiment, the method comprises prior to step (b) step (cc): (cc) deprotecting the compound of formula Va (O-Va or S-Va) obtained in step (B) or (C) as defined in the first aspect by removing the R groups, i.e. the acyl protecting groups, using hydrogen bromide in acetic acid in the presence of a pharmaceutically acceptable anion.

Embodiment 3: Subjecting a compound of formula O-Va or S-Va to ion exchange with chloride or another pharmaceutically acceptable anion, followed by deprotection

In a further specific embodiment, it is also possible to exchange the bromide in a compound of formula O-Va or S-Va by chloride in an ion-exchanger loaded with chloride anions, and to subsequently deprotect the formed product O-Vb or S-Vb, i.e. to cleave the acyl groups from the riboside, when the formed product is subjected to hydrogen chloride.

O-Vb S-Vb

[001 15] Accordingly, in a specific embodiment, the invention relates to a method of making a compound of formula O-lb or S-lb, comprising step (d):

(d) subjecting the crystalline compound of formula O-Va or S-Va as defined in the first aspect to ion exchange using an ion exchanger loaded with chloride ions.

[001 16] Subsequently, the product obtained in step (d) is subjected to hydrochloric acid in order to deprotect the product formed in step (d), i.e. to cleave the acyl groups in order to obtain the target compound.

[001 17] Accordingly, the method comprises step (e):

(e) subjecting the product formed in step (d) to hydrogen chloride. [001 18] In a more general embodiment, the crystalline compound of formula O-Va or S- Va as defined in the first aspect is subjected to ion exchange using an ion exchanger loaded with a pharmaceutically acceptable anion, and subsequently the product formed by ion exchange is subjected to the acid of the pharmaceutically acceptable anion, i.e. to the protonated pharmaceutically acceptable anion in order to deprotect the product formed in the ion exchange step, i.e. to cleave the acyl groups in order to obtain the target compound.

[001 19] Thus, in a more general embodiment, the invention relates to a method of making a crystalline (thio)nicotinamide-3-D-ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion, comprising steps (d) and (e):

(d) subjecting the crystalline compound of formula O-Va or S-Va as defined in the first aspect to ion exchange using an ion exchanger loaded with a pharmaceutically acceptable anion;

(e) subjecting the product formed in step (d) to the protonated pharmaceutically acceptable anion.

[00120] It may be advantageous to perform the ion exchange according to embodiment 3, i.e. starting from (thio)nicotinamide-2,3,5-tri-0-acyl-3-D-riboside bromide of formula O- Va or of formula S-Va since compared to a compound of formula Va (thio)nicotinamide- b-D-ribofuranoside bromide of formula O-la or S-la commonly has a lower stability in water, respectively a worse solubility in organic solvents.

[00121 ] The salts such as (thio)nicotinamide-2,3,5-tri-0-acyl-3-D-ribofuranoside bromide of formula Va and target salts such as (thio)nicotinamide-3-D-ribofuranoside bromide of formula la and (thio)nicotinamide-3-D-ribofuranoside chloride of formula lb made according to the methods of the invention are obtained in crystallized form. The amides are white to pale yellow solids, which are colorless in solution whereas the thioamides are bright yellow solids.

[00122] Crystallization may be evidenced by means of the respective powder X-ray diffraction patterns.

Crystalline (thio)nicotinamide- -D-ribofuranoside salts (third aspect) [00123] According to a third aspect, in one embodiment, the invention relates to a crystalline nicotinamide-2, 3, 5-tri-0-acetyl-3-D-ribofuranoside bromide of formula O-Va, wherein R = acetyl, characterized by a powder X-ray diffraction pattern as defined in Fig. 1.

[00124] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 1 , below, ± 0.2 degrees two theta:

Pos [°2Th.] Height [ctsj FWHM Left [°2Th.J d-spacing [A] Rel. Int. [%]

4.8596 71292.27 0.0512 18 18452 100.00

9.7415 37099.07 0.0640 9 07962 52.04

11 0636 5303.51 0 0512 7 99743 7.44

11.6661 30006.17 0.0640 7.58568 42.09

12.5050 17088.05 0.0640 7.07866 23.97

14 1694 10910.62 0.0640 6.25069 15 30

14.3467 12561.22 0.0640 6.17384 17 62

14.6404 11886.06 0.0640 6.05064 16 67

15 0039 688.76 0.0768 5.90486 0.97

15.4402 22972.38 0.0640 5.73897 32.22

15.6066 12142.07 0.0768 5.67815 17.03

16.0891 7318.08 0.0768 5.50895 10.26

17.5371 5753.52 0.0640 5.05719 8.07

18.2959 29604.23 0.0768 4.84915 41.53

18.9874 4361.61 0.0512 4.67407 6.12

19.2100 20055.34 0.0640 4.62041 28.13

19.5686 65927.24 0 0895 4.53654 92.47

21.0763 6048.25 0,0640 4.21531 8.48

21.5928 24667.1 0 0512 4.1 1563 34.60

21.7919 68197.61 0 0768 4.07847 95.66

22.2517 51038.13 0 0640 3.99523 71.59

22.6057 16893.10 0.0640 3.93345 23.70

22.8833 3286.77 0.0640 3.88636 4.61

23.6485 9504.24 0.0512 3.76232 13.33

24.5338 1713.25 0.0640 3.62852 2.40

25.2389 6926.32 0.0640 3.52872 9.72

25.5511 2626.48 0 0512 3.48632 3.68

25.7810 10528.73 0 0512 3.45575 14.77

25.9964 46928.79 0 0768 3.42760 65.83

26.2806 27519.44 0 0640 3.391 18 38.60

26.4612 15615.08 0 0512 3.36843 21.90

26.6836 9655.02 0 0640 3.34087 13.54

27.8914 10858.11 0 0640 3 19888 15 23

28.3122 16888.73 0.0768 3.15229 23.69

28.5824 10649.71 0 0640 3.12310 14.94

28.9526 2577.58 0 0640 3.08400 3.62

29.6768 7952.96 0.0768 3.01037 11.16

29.9687 5882.39 0 0780 2.97925 8.25

30.0860 4650.26 0.0768 2.97036 6.52

30.3809 9160.45 0.0640 2.94219 12.85

30.6233 5333.30 0.0512 2.91946 7.48

31.1502 5948.54 0.0768 2.87126 8.34

31.5383 983.58 0.0512 2.83681 1.38

31.7362 6573 29 0.0624 2.81724 9.22

31.8393 6262.96 0 0768 2 81067 8.78

32.3004 2514.90 0 0512 2.77160 3.53

32 5427 4936.80 0 0512 2.75151 6.92

32.7422 671 1.15 0 0512 2.73520 9.41

33.5611 3857.26 0 0512 2.67031 5 41

34.0690 1950.96 0 0936 2.62948 2.74

Table 1

[00125] In another embodiment, the invention relates to crystalline nicotinamide-3-D- ribofuranoside bromide of formula O-la characterized by a powder X-ray diffraction pattern as defined in Fig. 2. [00126] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 2, below, ± 0.2 degrees two theta:

Pos. [°2Th.j Height [ctsj h'WHM Left [°24h.J d-spacing |Aj Rel. Int. [%]

4.9834 3991585 00640 1773310 38.04

9.9926 10492560 0.0768 8.85207 100.00

12.7289 748857 0.0895 6.95464 7.14

15.0281 4745.79 0.0640 5.89541 4.52

15.4178 4309999 00895 574727 41.08

17.1678 9579.68 00895 516515 9.13

17.7747 93087 01023 4.99013 0.89

18.2972 236750 0.0895 4.84879 2.26

19.1099 2108264 01151 4.64438 20.09

20.0800 10612.44 0.1023 4.42214 10.11

21.1406 19432.96 0.0512 4.20263 18.52

213367 81187.77 01023 4.16445 77.38

217779 934333 00895 4.08106 890

225050 23707.08 01023 3.95082 22.59

232212 5321899 0.1023 3.83057 50.72

23.4862 2792412 0.1023 3.78795 26.61

236753 1424562 00768 375812 13.58

24.0921 550.38 0.1279 3.69403 0.52

24.7343 20396.95 0.1151 3.59955 19.44

249572 36507.45 0.0768 3.56791 34.79

251805 77901.20 0.1151 3.53677 7424

255555 56498.90 0.1092 3.48284 53.85

256308 36562.21 0.0468 3.48141 34.85

26.0811 60634.70 0.1092 3.41383 5779

267636 978.36 0.1560 3.32830 093

276511 30326.81 0.0780 3.22346 28.90

278528 34745.99 0.0936 3.20058 33.11

27.9323 17571.27 0.0468 3.19958 16.75

288151 322091 0.0936 3.09584 3.07

293715 8276.64 0.0780 303845 7.89

29.5362 17269.12 0.0780 3.02188 16.46

29.6387 10238.93 0.0624 3.01914 9.76

299900 2526.55 0.0936 2.97718 2.41

303279 73767.23 0.0936 2.94477 7030

304006 45680.79 0.0468 2.94520 43.54

308843 2342.44 0.0936 2.89297 2.23

31.2148 3499.82 0.0936 2.86309 3.34

322063 6972.10 00624 2.77718 6.64

32.6193 4935.69 0.0780 2.74296 4.70

328912 10921.30 0.0780 2.72090 10.41

333108 7332.05 0.0936 2.68757 6.99

350536 35425.14 0.0780 2.55784 3376

351640 43507.22 0.0780 2.55007 41.46

352887 16436.92 0.0468 2.54765 15.67

355397 13765.55 0.0780 2.52396 13.12

360064 16502.96 0.0936 2.49231 15.73

361080 7558.48 0.0468 2.49171 7.20

364748 4177.84 0.0936 2.46137 3.98

367106 3655.13 0.0780 2.44610 3.48

37.3013 3317.08 0.0624 2.40872 3.16

Table 2 [00127] In another embodiment, the invention relates to a crystalline nicotinamide- 2, 3, 5-tri-0-acetyl-3-D-ribofuranoside chloride of formula O-Vb characterized by a powder X-ray diffraction pattern as defined in Fig. 3.

[00128] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 3, below, ± 0.2 degrees two theta:

Pos. [°2Th.] Height [cts] FWHM Left [°2Th.] d-spacing [A] Rel. int. [%J

4.8475 6417.96 00512 1822981 10.38

9.7319 4639697 00768 9.08855 7506

111326 222254 00895 7.94800 3.60

117525 775180 01151 753014 1254

12.5411 269325 0.1023 705833 436

14.1524 8155.33 0.1151 6.25815 1319

14.4494 1974800 01279 6.13020 31.95

146138 730556 00640 606157 11.82

154504 3780.59 0.0768 5.73520 612

15.8654 6665.39 0.1151 5.58609 10.78

16.3153 11068.90 0.1151 5.43308 1791

18.5224 19458.24 0.1279 4.79034 3148

19.1777 24721.89 0.1279 4.62812 4000

19.5514 47962.12 0.1023 4.54049 77.60

21.3779 4494.25 0.0768 4.15651 7.27

21.6771 21463.64 0.0895 4.09981 34.72

21.9841 61810.63 0.1151 4.04325 100.00

22.4229 23441.39 0.1023 3.96511 37.92

22.7501 5967.33 0.0895 3.90881 9.65

239418 5090.24 0.1151 3.71689 8.24

25.4363 4660.75 0.1023 3.50179 7.54

25.9756 4050.70 0.0780 3.42745 6.55

26.0480 3956.44 0.0512 3.42093 6.40

26.5839 35761.91 0.1407 3.35317 57.86

26.7937 8733.41 0.0512 3.32739 14.13

27.0585 10338.22 0.1023 3.29542 16.73

27.9629 5175.38 0.1279 3.19086 8.37

28.4388 8827.46 0.1279 3.13854 14.28

28.9342 4867.77 0.1023 3.08592 7.88

29.1871 9899.74 0.1151 3.05976 16.02

29.5207 3827.12 0.1023 3.02594 6.19

30.2684 4111.40 0.1023 2.95287 6.65

30.4970 3424.80 0.0768 2.93125 5.54

30.6819 2181.97 0.0512 291401 3.53

30.9229 3888.20 00895 289185 6.29

31.5061 1895.93 0.0895 283963 3.07

31.9376 3794.97 0.0895 2.80225 6.14

32.6368 122155 0.1535 2.74379 1.98

33.0340 2110.89 0.0768 271170 3.42

33.2355 2214.18 0.0640 2.69572 3.58

33.8728 2956.74 0.0768 2.64645 4.78

34.5515 2843.73 0.1023 2.59600 4.60

34.7925 797030 0.0768 257857 12.89

35.0864 2845.65 00895 2.55764 4.60

35.4559 5572.16 0,0895 2.53183 9.01

35.7436 8015.40 00780 2.51003 12.97

35.9103 10571.39 01151 250083 17.10

36.4863 901.67 01023 246266 146

37.0231 2078.04 0.0895 242818 3.36

37.3756 1277.41 0.0768 240609 2.07

Table 3

[00129] In another embodiment, the invention relates to a crystalline nicotinamide-3-D- ribofuranoside chloride of formula O-lb characterized by a powder X-ray diffraction pattern as defined in Fig.4. [00130] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 4, below, ± 0.2 degrees two theta:

Pos. [°2Th.] Height [cts] FWHM Left [°2Th.] d- spacing [A] Rel. Int. [%]

5.0231 8989.67 . 0.0384 17.59305 39.07

12.1684 2813.03 0.0512 7.27371 12.22

14.1132 1403.11 0.0640 6.27546 6.10

15.6279 8040.27 0.0512 5.67047 34.94

17.3905 290.12 0.0768 5 09950 1.26

18.5579 9325.1 5 0.0768 4 78127 40.52

19.4055 2040.30 0.0640 4 57430 8.87

20.2755 328.10 0.0768 4 37994 1.43

21.6623 23012.07 0.0768 4 10258 100.00

21.9250 2287.87 0.0512 4.05402 9.94

22.1043 3821.40 0.0512 4 02153 16 61

22.8310 2687.12 0.0640 3.89514 11.68

23.5039 4901.46 0.0512 3 78513 21.30

23.8061 6551.87 0.0512 3 73777 28.47

24.0791 2424.61 0.0512 3 69600 10.54

24.4847 304.96 0.0768 3.63569 1.33

25.0212 1591.60 0.0512 3,55893 6.92

25.2426 4900.73 0.0384 3.52822 21.30

25.4137 1375.46 0.0384 3.50484 5.98

25.8290 1207.51 0.0384 3.44943 5.25

26.0464 1224.32 0.0512 3.42113 5.32

26.4267 7816.55 0.0512 3 37276 33.97

28 0059 4178.39 0.0384 3.18607 18 16

28.1526 1630.03 0.0384 3.16980 7.08

29.1551 207.40 0.1023 3.06304 0.90

29.7413 197.40 0.0768 3.00399 0.86

30.0261 1277.41 0.0624 2.97368 5.55

30.1291 1167.49 0.0468 2.9711 1 5.07

30.6207 899.57 0.0624 2.91727 3.91

31.0112 1136.20 0.0624 2.88142 4.94

31.5753 873.21 0.0624 2.83122 3.79

32.6926 413.90 0.0624 2.73697 1.80

32.9720 120.06 0.1248 2.71441 0.52

33.3259 934.40 0.0624 2.68639 4.06

33.7902 2305.04 0.0468 2.65053 10.02

35.0795 663.05 0.0624 2 55601 2 88

35.4164 1125.19 0.0780 2.53247 4.89

35 5939 1969.88 0.0468 2.52025 8.56

35.6948 731.01 0.0468 2.51959 3.18

35.8891 190.71 0.0936 2.50019 0.83

36.5129 1149.56 0.0624 2.45889 5.00

36.6270 1264.06 0.0624 2.45149 5.49

36.7356 505.49 0.0468 2.45057 2.20

36.9895 579.35 0.0468 2.42830 2.52

37.0895 896.19 0.0468 2.42198 3.89

37.7257 287.11 0.0624 2.38258 1.25

38.0622 290.59 0.0624 2.36229 1.26

38.2889 929.40 0.0624 2.34883 4 04

38.5465 1392.21 0.0624 2.33372 6 05

39 2478 426.81 0.0468 2 29362 1.85

Table 4 [00131 ] In another embodiment, the invention relates to a crystalline thionicotinamide- 2,3,5-tri-0-acetyl-3-D-ribofuranoside bromide of formula S-Va characterized by a powder X-ray diffraction pattern as defined in Fig. 5.

[00132] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 5, below, ± 0.2 degrees two theta:

Table 5 [00133] In another embodiment, the invention relates to a crystalline thionicotinamide- b-D-ribofuranoside bromide of formula S-la characterized by a powder X-ray diffraction pattern as defined in Fig. 6.

[00134] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 6, below, ± 0.2 degrees two theta:

Pos. [°2Th.J Height [ctsj FWIJM Left [°2Th] d-spaclng [A] Rel. Int. [%]

4.8203 2278.31 00768 18.30980 803

9.6801 14078.37 00895 9.13713 4960

12.6028 2173.34 01279 7.02393 766

14.5631 352.02 01535 608257 124

15.1699 10647.52 0.1279 584062 3751

16.8482 98208 0.1535 526240 346

18.0591 25763 02047 4.91219 091

18.6922 611769 0.1151 474722 2155

19.4549 9894.90 01023 4.56280 34.86

20.6633 3359.40 01279 429860 11.84

21.1290 17624.66 0.1791 420490 62.09

21.5537 1681,31 0.1023 4.12301 5.92

22.2306 333813 0.1407 399897 11.76

22.7431 981891 0.1663 .3.91001 34.59

23.1593 737057 0.1407 3.84066 25.97

23.5649 662776 0.1407 3.77547 23.35

23.9657 2892.60 0.1407 3.71323 10.19

24.3932 28384.03 0.1791 3.64912 100.00

24.8879 9967.23 0.1279 3.57770 35.12

25.3853 319946 0.1023 3.50871 11.27

256331 914939 0.1407 3.47534 32.23

264737 190594 0.1279 3.36688 6.71

271198 2310726 0.1791 3.28811 81.41

28.1027 1337.27 0.1279 3.17531 4.71

28.7725 4230.01 0.1407 3.10289 14.90

29.3727 24117.60 0.1248 3.03832 84.97

29.4398 20316.94 0.0624 3.03908 71.58

30.2656 2777.86 0.0936 2.95069 9.79

30.5945 2989.91 0.1248 2.91971 10.53

318537 1694.75 0.1092 2.80711 5.97

32.3235 5502.72 0.1716 2.76737 19.39

329021 1649.42 0.1872 2.72002 5.81

340540 6762.12 0.1248 2.63060 23.82

343285 6745.81 0.1248 2.61020 23.77

354687 2867.35 0.2340 2.52885 10.10

359066 2636.15 0.3120 2.49901 9.29

36.4103 4708.75 0.1716 2.46558 16.59

36.9346 2540.82 0.1248 2.43178 8.95

37.3399 1585.95 0.1872 2.40631 5.59

37.6298 2307.02 0.1560 2.38844 8.13

37.9333 1564.59 0.2184 2.37002 5.51

38.5213 2557.83 0.1092 2.33519 9.01

38.8557 2678.86 0.1248 2.31586 9.44

39.5049 8914.12 0.1092 2.27928 31.41

39.5830 8086.04 0.0780 2.28061 28.49

40.5200 1109.47 0.1404 2.22449 3.91

41.1098 2048.76 0.2184 2.19393 7.22

41.7700 1066.47 0.1560 2.16077 3.76

419990 779.91 0.1872 2.14951 2.75

42.8567 2660.17 0.1248 2.10846 9.37

Table 6

[00135] In another embodiment, the invention relates to crystalline thionicotinamide-b- D-ribofuranoside chloride of formula S-lb characterized by a powder X-ray diffraction pattern as defined in Fig.7. [00136] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 7, below, ± 0.2 degrees two theta:

Pos. [°2Th.l Height [cts] FWHM Left [°2Th.l d-spacing [A] Rel. Int. [%1

5.1072 2596.08 0.1407 17.30350 12.31

9.9887 750.86 0.1535 8.85552 3.56

12.3314 2986.69 0.0895 7.17791 14.17

14.1590 596.22 0.2047 6.25523 2.83

14.9235 770.31 0.1535 5.93649 3.65

15.5744 8180.18 0.1716 5.68511 38.80

15.6423 7419.05 0.0780 5.67464 35.19

17.2676 554.86 0.2496 5.13128 2.63

18.4501 3815.59 0.2496 4.80498 18.10

19.2735 1749.74 0.1248 4.60152 8.30

21.6073 21083.66 0.3276 4.10949 100.00

22.0435 3617.26 0.1248 4.02915 17.16

22.7953 2232.49 0.2184 3.89794 10.59

23.1851 4285.33 0.2496 3.83327 20.33

23.6470 5385.96 0.2340 3.75944 25.55

24.2027 4758.83 0.1248 3.67437 22.57

24.8374 13692.29 0.2496 3.58189 64.94

25.2280 3183.22 0.1560 3.52731 15.10

26.0958 7252.40 0.1248 3.41195 34.40

26.1900 7230.56 0.0780 3.40834 34.29

27.6167 10363.59 0.2496 3.22740 49.15

28.5770 1049.57 0.2808 3.12109 4.98

29.2742 1090.63 0.3120 3.04833 5.17

29.8993 2582.37 0.3120 2.98600 12.25

30.1497 1826.12 0.1872 2.96177 8.66

30.9751 1763.02 0.2496 2.88470 8.36

31.1711 1963.57 0.3432 2.86701 9.31

32.9684 1435.80 0.3120 2.71470 6.81

33.6199 770.78 0.1872 2.66357 3.66

34.8531 3520.86 0.3744 2.57210 16.70

36.1670 972.10 0.2496 2.48162 4.61

36.7771 1506.66 0.2808 2.44183 7.15

37.9104 1370.92 0.5616 2.37140 6.50

39.2448 901.73 0.3744 2.29378 4.28

40.0799 1048.09 0.2808 2.24790 4.97

40.8062 428.39 0.1872 2.20955 2.03

41.2829 782.56 0.1872 2.18513 3.71

41.7217 1452.32 0.3120 2.16315 6.89

42.6907 809.28 0.3120 2.11627 3.84

43.5291 1167.24 0.3744 2.07744 5.54

44.4617 535.56 0.2184 2.03600 2.54

Table 7 [00137] In another embodiment, the invention relates to crystalline thionicotinamide- 2,3,5-tri-0-acetyl-3-D-ribofuranoside chloride of formula S-lb characterized by a powder X-ray diffraction pattern as defined in Fig. 8.

[00138] The crystalline form may also be characterized by a powder X-ray diffraction pattern having peaks substantially as provided in Table 8, below, ± 0.2 degrees two theta:

Pos. f°2Th.1 Height ctsl FWHM Left [ ⁰ 2Th | Rel. Int. [%]

4.7629 30989.72 0.0640 18.55331 48.42

9.5228 64007.27 0.0640 9.28763 100.00

11.2966 1385.84 0.1023 7.83301 2.17

12.0273 2951.19 0.0768 7.35867 4.61

13.1540 8423.38 0.1023 6.73083 13.16

13.8503 5372.95 0.0895 6.39396 8.39

14.0546 7164.81 0.0768 6.30149 11.19

14.2991 18424.71 0.0768 6.19426 28.79

14.5992 11231.60 0.1023 6.06762 17.55

15.3559 6070.71 0.1023 5.77026 9.48

15.5853 2908.67 0.1023 5.68586 4.54

16.2590 5787.38 0.0895 5.45174 9.04

16.8212 4919.45 0.1151 5.27078 7.69

17.4532 776.59 0.1279 5.08132 1.21

18.0942 13123.85 0.0895 4.90274 20.50

18.2901 1790.00 0.0640 4.85066 2.80

18.8734 15468.63 0.0895 4.70205 24.17

19.1009 31383.10 0.0895 4.64654 49.03

20.0535 4701.27 0.0768 4.42793 7.34

20.4586 3815.57 0.1663 4.34116 5.96

20.9713 273.54 0.1279 4.23616 0.43

21.6672 ‘ 2891.86 0.0895 4.10167 4.52

22.1146 32720.12 0.0895 4.01969 51.12

22.2611 15800.38 0.0640 3.99355 24.69

22.7144 13549.10 0.1023 3.91487 21.17

23.1129 1558.49 0.1023 3.84828 2.43

23.6820 10056.44 0.1407 3.75707 15.71

23.9397 6079.45 0.0640 3.71720 9.50

24.1967 4206.54 0.1023 3.67830 6.57

25.0234 9998.71 0.1663 3.55862 15.62

25.6685 2351.72 0.1151 3.47064 3.67

26.4926 27607.33 0.1535 3.36452 43.13

27.3692 457.49 0.1023 3.25872 0.71

27.7114 2170.01 0.1023 3.21925 3.39

28.3345 1296.60 0.1023 3.14986 2.03

28.8200 12758.68 0.0640 3.09788 19.93

29.4666 1007.19 0.1279 3.03137 1.57

29.8579 3055.67 0.1663 2.99253 4.77

30.4167 1023.68 0.1535 2.93881 1.60

30.9424 1283.06 0.1023 2.89007 2.00

31.4066 2975.43 0.1151 2.84840 4.65

32.0957 2236.40 0.0895 2.78880 3.49

32.4438 1464.86 0.1023 2.75968 2.29

32.7074 3906.59 0.0895 2.73803 6.10

33.2688 2057.43 0.0768 2.69310 3.21

33.6753 6189.38 0.0624 2.65931 9.67

33.7459 6110.92 0.0512 2.65611 9.55

34.0335 2807.78 0.1151 2.63432 4.39

34.3454 3056.34 0.0640 2.61110 4.77

34.6680 3159.91 0.0895 2.58755 4.94

Table 8 [00139] In another embodiment, the invention relates to a crystalline compound of formula la (O-la or S-la) or lb (O-lb or S-lb) wherein the compound bears instead of the bromide ion or chloride anion another pharmaceutically acceptable anion such as an anion of sulfuric acid or phosphoric acid.

[00140] In another embodiment, the compound of formula la is obtainable by the method as defined in the first aspect.

[00141 ] In another embodiment, the compound of formula lb is obtainable by the method as defined in the second aspect.

Use of crystalline (thio)nicotinamide- -D-ribofuranoside bromide and pharmaceutically acceptable salts thereof (fourth aspect)

[00142] According to a fourth aspect, in one embodiment, the invention relates to the use of a (thio)nicotinamide-3-D-ribofuranoside bromide of formula la or of a (thio)nicotinamide-3-D-ribofuranoside chloride of formula lb obtainable by a method as defined in the first or second aspect, or to the use of a (thio)nicotinamide-3-D- ribofuranoside bromide of formula la or (thio)nicotinamide-3-D-ribofuranoside chloride of formula lb defined in the third aspect as nutritional supplement.

[00143] In another embodiment, the invention relates to the use of a (thio)nicotinamide- b-D-ribofuranoside chloride of formula lb obtainable by a method defined in the second aspect, or to the use of a (thio)nicotinamide-3-D-ribofuranoside chloride of formula lb defined in the third aspect as nutritional supplement, wherein the compound bears instead of the chloride anion as pharmaceutically acceptable anion another pharmaceutically acceptable anion, preferably an anion of sulfuric acid or phosphoric acid.

[00144] In another embodiment, the invention relates to a pharmaceutical composition comprising a (thio)nicotinamide-3-D-ribofuranoside bromide of formula la or (thio)nicotinamide-3-D-ribofuranoside chloride of formula lb obtainable by a method defined in the first or second aspect or comprising a (thio)nicotinamide-3-D- ribofuranoside bromide of formula la or a (thio)nicotinamide-3-D-ribofuranoside chloride of formula lb defined in the third aspect. [00145] In another embodiment, the invention relates to a pharmaceutical composition comprising a (thio)nicotinamide-3-D-ribofuranoside chloride of formula lb obtainable by a method defined in the second aspect, or comprising a (thio)nicotinamide-3-D- ribofuranoside chloride of formula lb defined in the third aspect, wherein the compound bears instead of the chloride anion as pharmaceutically acceptable anion another pharmaceutically acceptable anion, preferably an anion of sulfuric acid or phosphoric acid.

[00146] In one embodiment, the (thio)nicotinamide-3-D-ribofuranoside bromide or chloride of formula la or lb or the compound lb bearing instead of the chloride anion as pharmaceutically acceptable anion another pharmaceutically acceptable anion, preferably an anion of sulfuric acid or phosphoric acid, are used in the prevention or treatment of diseases or conditions associated with the nicotinamide riboside kinase pathway or other pathways of NAD ⁺ biosynthesis. These pathways are known in the art.

Method of making a supported (thio)nicotinamide- -D-ribofuranoside salt (fifth aspect)

[00147] In a fifth aspect, the invention relates to a method of making a supported (thio)nicotinamide-3-D-ribofuranoside salt, wherein the (thio)nicotinamide-3-D- ribofuranoside salt is a salt as defined in the second aspect.

[00148] The method comprises a method as defined in the second aspect, and further comprises step (F):

(F) contacting a carrier with the (thio)nicotinamide-3-D-ribofuranoside salt, wherein the anion of the salt is a pharmaceutically acceptable anion, and one or more solvents.

[00149] Contacting as defined in step (F) may be simply performed by mixing.

[00150] Preferably, the (thio)nicotinamide-3-D-ribofuranoside salt is prepared according to the method as defined in the second aspect.

[00151 ] Preferably, the one or more solvents is/are water or contain water. In one embodiment, the educts are provided as aqueous solutions [00152] In order to isolate and solidify the target compound, the method further requires the removal of the one or more solvents.

[00153] Accordingly, the method further comprises step (G):

(G) removing the one or more solvents from the mixture obtained in step (F).

[00154] Removing the one or more solvents as defined in step (G) may be performed by distilling off the solvent, or preferably by lyophilisation.

[00155] The term “ carrier” as used herein is synonymously used with the term “support’.

[00156] Suitable carriers, may include, for example, calcium phosphate, silicon dioxide, magnesium stearate, talc, sugars, pullulan, lactose, dextrin, starch, gelatin, cellulose, methyl cellulose, ethylcellulose, sodium carboxymethyl cellulose, microcrystalline cellulose, polyvinylpyrrolidine, low melting waxes, ion exchange resins, croscarmellose carbon, acacia, pregelatinized starch, crospovidone, HPMC, povidone, titanium dioxide, polycrystalline cellulose, aluminum metahydroxide, agar-agar, tragacanth, or mixtures thereof.

[00157] A preferred carrier is pullulan.

[00158] The term“pullulan" encompasses the various types of pullulanes which are known in the field of pharmaceutical applications.

[00159] In one embodiment, the one or more solvent/solvents is/are selected from pharmaceutically acceptable solvents as are known in the art. In one embodiment, the solvent is water or comprises water.

[00160] At least in case of pullulan used as support, the supported (thio)nicotinamide-3- D-ribofuranoside salt is typically obtained as an optical clear, glass-like material or as a white solid. This solid typically is amorphous as may be shown by XRD analyses which do not provide for sharp peaks which would indicate the presence of crystals.

Composition comprising a (thio)nicotinamide- -D-ribofuranoside salt and a carrier (sixth aspect) [00161 ] According to a sixth aspect, the invention relates to a composition comprising a (thio)nicotinamide-3-D-ribofuranoside salt and a carrier.

[00162] Preferably, the (thio)nicotinamide-3-D-ribofuranoside salt is prepared according to the method as defined in the second aspect, and the composition is prepared according to the method as defined in the fifth aspect.

[00163] Further preferably, the carrier is a carrier as defined in the fifth aspect, preferably pullulan.

[00164] The composition defined in the sixth aspect may be used for the same applications or uses as defined in the fourth aspect.

Method of making a tri-0-acyl- -D-ribofuranoside bromide of formula III (seventh aspect)

[00165] According to a seventh aspect, the invention relates to a method of making a tri-0-acyl-3-D-ribofuranoside bromide of formula III

the method comprising step (a):

(a) subjecting a tetra-0-acyl-3-D-ribofuranose of formula wherein each R is independently selected from acyl,

to hydrogen bromide in acetic acid.

Method of removing acyl groups from (thio)nicotinamide-2,3,5-tri-0-acetyl- -D- ribofuranoside bromide or chloride (eighth aspect)

[00166] According to an eighth aspect, the invention relates to a method of removing the acyl groups from a compound of formula O-V, wherein each R is independently selected from acyl,

or of formula S-V

the method comprising step (i) or (ii):

(i) reacting the compound of formula O-V or formula S-V with hydrogen bromide in acetic acid; (ii) reacting the compound of formula O-V or formula S-V with hydrogen chloride in methanol.

EXAMPLES

[00167] The following Examples further illustrate the present invention.

Example 1 : Preparation of nicotinamide-2, 3, 5-tri-0-acetyl- -D-ribofuranoside bromide (a compound of formula O-Va)

[00168] 274 g b-D-ribofuranose 1 ,2,3,5-tetraacetate were dissolved in 274 ml acetonitrile. 180 ml of hydrogen bromide in glacial acetic acid (concentration 33 %) were added to the stirred solution while keeping the temperature between 0 °C and 5 °C. Stirring was continued for further 15 minutes. 41 g of nicotinamide was added while stirring for another 15 minutes. A hot (70 °C) solution of 96 g nicotinamide in 700 ml acetonitrile was then added whereupon the mixture was cooled to about 0 °C to 5 °C. Stirring was continued for 15 h, followed by filtration of the formed suspension. The filtrate was subjected to distillation. The obtained oily residue was diluted with acetone, resulting in crystallization of the title product. The title product was filtered and dried to give 167 g (43 % yield) of an almost colorless product; Mp: 133-134 °C.

¹ H-NMR (400 MHz, DMSO-d6): 2.09 (s, 6H), 2.13 (s, 3H) 4.45 (m, 2H, H5’), 4.69 (m, 1 H, H4’), 5.43 (t, 1 H, H3’), 5.62 (dd, 1 H, H2’), 6.69 (d, 1 H, H1’), 8.23 (s, 1 H, NH), 8.41 (dd, 1 H, H5), 8.74 (s, 1 H, NH), 9.13 (d, 1 H, H4), 9.28 (d, 1 H, H6), 9.49 (s, 1 H, H2);

¹³ C-NMR (100 MHz, DMSO-d6): 20.3, 20.4, 20.5, 62.1 (C5‘), 68.7 (C3‘), 75.3 (C2‘), 81.8 (C4‘), 97.2 (C1‘), 128.1 (C5), 133.9 (C3), 141.2 (C2), 143.1 (C6), 145.5 (C4), 162.7 (CONH2), 169.2, 169.4, 170.1.

Example 2: Preparation of nicotinamide- -D-ribofuranoside bromide of formula O- la

[00169] 167 g of the product obtained in Example 1 were dissolved in 870 ml methanol. 135 ml of hydrogen bromide in acetic acid (concentration 33 %) were then added to the stirred solution while keeping the temperature between 5 °C to 10 °C. The resulting mixture was stirred for two days at 20 °C wherein the product started crystallizing. The formed crystals were filtered off, washed with isopropanol and dried. The title compound was obtained in a yield of 77 g (63 %) as a pale yellow crystalline powder; Mp: 1 18-1 19 °C. ¹ H-NMR (400 MHz, D ₂ 0): 3.83 (dd, 1 H, H5’), 3.98 (dd, 1 H, H5’), 4.29 (t, 1 H, H3’), 4.39- 4.48 (m, 2H, H4’, H2’), 6.18 (d, 1 H, H1’), 8.22 (t, 1 H, H5), 8.91 (d, 1 H, H4), 9.20 (d, 1 H, H6), 9.52 (s, 1 H, H2);

¹³ C-NMR (100 MHz, D ₂ 0): 60.0 (C5‘), 69.5 (C3‘), 77.2 (C2‘), 87.5 (C4‘), 99.7 (C1‘), 128.3 (C5), 133.7 (C3), 140.2 (C2), 142.5 (C6), 145.5 (C4), 165.6 (C0NH2).

Example 3: Preparation of nicotinamide^-D-ribofuranoside chloride of formula O- Ib

[00170] 25 g of the product obtained in Example 2 were dissolved in 140 ml water and 140 g of ion exchange resin Amberlite IRA-402 (Cl-Form) were added and stirred for two hours. The resin was removed by filtration and washed with 140 ml water. To the filtrate were added 105 g of ion exchange resin, again stirred for two hours, filtered and washed with 40 ml water. This exchange was repeated further two times using 105 g of ion exchanger each. The final filtrate was evaporated to give 21.8 g of a clear, pale yellow resin. This resin was dissolved in a hot mixture of 100 ml ethanol and 100 ml methanol. The crystals obtained after cooling in an ice bath were filtered, washed with isopropanol and dried to give 12.8 g (59 %) of the title compound as colorless crystals. The bromide content was below 0.1 %. Mp: 123-124 °C.

¹ H-NMR (400 MHz, D ₂ 0): 3.84 (dd, 1 H, H5’), 3.98 (dd, 1 H, H5’), 4.30 (t, 1 H, H3’), 4.40- 4.47 (m, 2H, H4’, H2’), 6.19 (d, 1 H, H1’), 8.22 (t, 1 H, H5), 8.92 (d, 1 H, H4), 9.21 (d, 1 H, H6), 9.54 (s, 1 H, H2);

¹³ C-NMR (100 MHz, D ₂ 0): 60.3 (C5‘), 69.8 (C3‘), 77.5 (C2‘), 87.7 (C4‘), 99.9 (C1‘), 128.5 (C5), 134.0 (C3), 140.4 (C2), 142.7 (C6), 145.7 (C4), 165.8 (CONH2).

Example 4: Preparation of nicotinamide- -D-ribofuranoside chloride / bromide (mixed salt of formula O-lb/O-la)

[00171 ] 10 g of the intermediate product obtained in Example 1 were dissolved in 50 ml methanol. 15 ml of hydrogen chloride in ethanol (concentration 6 moles per L) were then added to the stirred solution while keeping the temperature between 5 °C to 10 °C. The resulting mixture was stirred overnight at 20 °C whereby the product crystallized. The crystals were filtered off, washed with isopropanol and dried. The mixture of the title compounds was obtained in a yield of 4.6 g (73 %). The ratio of chloride to bromide was about 3:1.

Example 5: Preparation of thionicotinamide-2,3,5-tri-0-acetyl- -D-ribofuranoside bromide (a compound of formula S-Va)

[00172] 30 g b-D-ribofuranose 1 ,2,3,5-tetraacetate were dissolved in 30 ml acetonitrile. 19.8 ml of hydrogen bromide in glacial acetic acid (concentration 33 %) were added to the stirred solution while keeping the temperature between 0 °C and 5 °C. Stirring was continued for further 15 minutes. 4.5 g of thionicotinamide was added while stirring for another 15 minutes. A hot (65 °C) solution of 12 g thionicotinamide in 510 ml acetonitrile was then added whereupon the mixture was cooled to about 0 °C to 5 °C. Stirring was continued for 15 h at 0 °C, followed by filtration of the formed suspension. The filtrate was subjected to distillation. The obtained oily residue was diluted with a mixture (1 :1 ) of ethanol and isopropanol, resulting in crystallization of the title product which was filtered and dried to give 22 g (50 % yield) of yellow crystalline powder. Mp: 134 °C.

¹ H-NMR (400 MHz, DMSO-d6): 2.06 (s, 3H), 2.09 (s, 3H), 2.14 (s, 3H) 4.43 (m, 2H, H5’), 4.70 (m, 1 H, H4’), 5.43 (t, 1 H, H3’), 5.63 (dd, 1 H, H2’), 6.68 (d, 1 H, H1’), 8.31 (dd, 1 H, H5), 8.99 (d, 1 H, H4), 9.20 (d, 1 H, H6), 9.49 (s, 1 H, H2), 10.30 (s, 1 H, NH), 10.66 (s, 1 H, NH);

¹³ C-NMR (100 MHz, DMSO-d6): 20.3, 20.4, 20.6, 62.3 (C5‘), 68.9 (C3‘), 75.3 (C2‘), 82.0 (C4‘), 97.1 (C1‘), 127.6 (C5), 138.6 (C3), 140.4 (C2), 142.3 (C6), 144.2 (C4), 192.5 (CSNH2), 169.2, 169.4, 170.0.

Example 6: Preparation of thionicotinamide- -D-ribofuranoside bromide of formula S-la

[00173] 18.6 g of the product obtained in Example 5 were dissolved in 1 10 ml methanol. 14 ml of hydrogen bromide in acetic acid (concentration 33 %) were then added to the stirred solution while keeping the temperature between 5 °C to 10 °C. The resulting mixture was stirred for two days at 20 °C wherein the product started crystallizing. The suspension was cooled to 0 °C and the yellow crystals were filtered off, washed with isopropanol and dried. The title compound was obtained in a yield of 9.3 g (68 %). Mp: 123°C. ¹ H-NMR (400 MHz, D ₂ 0): 3.84 (dd, 1 H, H5’), 3.99 (dd, 1 H, H5’), 4.31 (t, 1 H, H3’), 4.38- 4.50 (m, 2H, H4’, H2’), 6.18 (d, 1 H, H1’), 8.15 (t, 1 H, H5), 8.83 (d, 1 H, H4), 9.13 (d, 1 H, H6), 9.60 (s, 1 H, H2);

¹³ C-NMR (100 MHz, D ₂ 0): 60.2 (C5‘), 69.7 (C3‘), 77.4 (C2‘), 87.5 (C4‘), 100.0 (C1‘), 128.0 (C5), 139.6 (C3), 139.9 (C2), 141.6 (C6), 143.8 (C4), 194.5 (CSNH2).

Example 7: Preparation of nicotinamide-2, 3, 5-tri-0-acetyl- -D-ribofuranoside bromide / chloride (a mixed salt of formula O-Va/O-Vb)

[00174] 274 g b-D-ribofuranose 1 ,2,3,5-tetraacetate were dissolved in 274 ml acetonitrile. 180 ml of hydrogen bromide in glacial acetic acid (concentration 33 %) were then added to the stirred solution while keeping the temperature between 0 °C to 5 °C. Stirring was continued for further 15 minutes. 41 g of nicotinamide was added while stirring for another 15 minutes. A hot (55 °C) solution of 96 g nicotinamide in 1 ,800 ml acetonitrile was then added whereupon the mixture was cooled to about 0 °C to 5 °C. Stirring was continued for 15 h, followed by filtration of the formed suspension. To the filtrate were added 3,600 g of strongly basic anion exchange resin Amberlite IRA-402 in the chloride form which had been washed with acetonitrile before use to remove humidity. The resin was stirred for three hours and then filtered off. The filtrate was subjected to distillation. The obtained oily residue was diluted with acetone, resulting in crystallization of the title product. The title product was filtered and dried to give 147 g (41 % yield) of an almost colorless product. The ratio of chloride to bromide was about 8:1. Mp: 141 °C.

¹ H-NMR (400 MHz, DMSO-d6): 2.10 (s, 6H), 2.14 (s, 3H) 4.47 (m, 2H, H5’), 4.69 (m, 1 H, H4’), 5.45 (t, 1 H, H3’), 5.65 (dd, 1 H, H2’), 6.70 (d, 1 H, H1’), 8.23 (s, 1 H, NH), 8.40 (dd, 1 H, H5), 9.07 (s, 1 H, NH), 9.13 (d, 1 H, H4), 9.26 (d, 1 H, H6), 9.31 (s, 1 H, H6), 9.63 (s, 1 H, H2);

¹³ C-NMR (100 MHz, DMSO-d6): 20.8, 20.9, 21.0, 62.7 (C5‘), 69.2 (C3‘), 75.7 (C2‘), 82.3 (C4‘), 97.2 (C1‘), 128.5 (C5), 134.4 (C3), 141.9 (C2), 143.6 (C6), 146.2 (C4), 163.1 (CONH2), 169.7, 169.9, 170.6. Example 8: Preparation of nicotinamide- -D-ribofuranoside chloride of formula O- Ib by deprotection of nicotinamide-2, 3, 5-tri-0-acetyl- -D-ribofuranoside chloride of formula O-Vb

[00175] General procedure: Nicotinamide-tri-0-acetyl-3-D-ribofuranoside chloride was dissolved in methanol (4.9 ml_/g). Afterwards 2 equivalents of a solution of hydrochloric acid in ethanol (7.6 N) was added dropwise and the reaction mixture was stirred for 4 h at r.t. The crude product was filtered, washed with isopropyl alcohol and methanol and dried over 48 hours under reduced pressure to yield the pure nicotinamide-3-D- ribofuranoside chloride as a white solid (49-64 %). a) Nicotinamide-tri-0-acetyl-3-D-ribofuranoside chloride = 1.95 kg (4.679 mol) in 9.5 L MeOH

7.6 N HCI (9.357 mol, 2.0 eq., 1.231 L)

4 h at r.t.

1 *2 L IPA, 1*2 L MeOH

Nicotinamide-3-D-ribofuranoside chloride = 672 g (2.312 mol, 49 %) b) Nicotinamide-tri-O-acetyl-beta-D-ribofuranoside chloride = 1.70 kg (4.079 mol) in 8.5 L MeOH

7.6 N HCI (2.0 eq., 8.157 mol, 1.073 L)

4 h at r.t.

1 *2 L IPA, 1 *2 L MeOH

Nicotinamide-3-D-ribofuranoside chloride = 757 g (2.604 mol, 64 %)

Purity (HPLC) 99.3 area-%

Impurity (Nicotinamide) 0.3 %

¹ H-NMR (400 MHz, D ₂ 0) d ppm 3.85 (dd, J=13.0, 3.5 Hz, 1 H) 3.96 - 4.03 (m, 1 H) 4.29 - 4.34 (m, 1 H) 4.40 - 4.50 (m, 2 H) 6.21 (d, J=4.6 Hz, 1 H) 8.24 (t, J=6.8 Hz, 1 H) 8.94 (d, J= 8.3 Hz, 1 H) 9.23 (d, J=6.1 Hz, 1 H) 9.55 (s, 1 H).

Examples 9 to 12: Preparation of nicotinamide- -D-ribofuranoside and nicotinamide-2, 3, 5-tri-0-acetyl- -D-ribofuranoside sulfate and phosphate salts using ion exchange resins [00176] Activation of the ion-exchange resin: 40 g Ambersep® 900 hydroxide form (The Dow Chemical Company) were rinsed with 250 ml_ 10% H ₂ S0 ₄ or 10% H ₃ P0 ₄ aqueous solution and washed with water until the pH-value of the washing solution remained constant.

[00177] General procedure: A solution of nicotinamide-3-D-ribofuranoside bromide of formula O-la or nicotinamide-2, 3, 5-tri-0-acetyl-3-D-ribofuranoside bromide of formula O- Va prepared according to the methods of the invention in water was filtered through the activated ion-exchange resin and lyophilized to afford the corresponding sulfate or dihydrogen phosphate as a solid:

[00178] Example 9: 4.0 g nicotinamide-tri-0-acetyl-3-D-ribofuranoside bromide (8.67 mmol; 1 eq) was dissolved in 15 mL water and filtered through 120 g H ₂ S0 ₄ -activated ion exchange resin, washed with 400 mL water and lyophilized to afford 3.71 g nicotinamide- tri-0-acetyl-3-D-ribofuranoside sulfate (7.77 mmol, 90 %) as a yellow solid.

[00179] Bromide content (IC): 0.0 %; Sulfate content (IC): 6.9 %; ¹ H-NMR (400 MHz, D ₂ 0) d ppm 2.1 1 (s, 3 H) 2.15 (s, 3 H) 2.18 (s, 3 H) 4.47 - 4.60 (m, 2 H) 4.84 - 4.98 (m, 1 H) 5.47 (t, J=5.4 Hz, 1 H) 5.59 (dd, J=5.4, 3.9 Hz, 1 H) 6.61 (d, J=3.8 Hz, 1 H) 8.30 (dd, J=8.0, 6.4 Hz, 1 H) 9.02 (dt, J=8.1 , 1.4 Hz, 1 H) 9.22 (ddd, J=6.2, 1.5 Hz, 1 H) 9.46 (s, 1 H).

[00180] Example 10: 1.3 g nicotinamide-tri-0-acetyl-3-D-ribofuranoside bromide (2.82 mmol; 1 eq) was dissolved in 5 mL water and filtered through 40 g H ₃ P0 ₄ -activated ion exchange resin, washed with 150 mL water and lyophilized to afford 1.27 g nicotinamide- tri-0-acetyl-3-D-ribofuranoside dihydrogen phosphate (2.66 mmol, 94 %) as a white solid.

[00181 ] Bromide content (IC): 0.0 %; Phosphate content (IC): 19.1 %

¹ H-NMR (400 MHz, D ₂ 0) d ppm 2.10 (s, 3 H) 2.14 (s, 3 H) 2.17 (s, 3 H) 4.45 - 4.61 (m, 2 H) 4.81 - 4.97 (m, 1 H) 5.46 (t, J=5.4 Hz, 1 H) 5.57 (dd, J=5.3, 4.0 Hz, 1 H) 6.60 (d, J=4.1 Hz, 1 H) 8.29 (t, J=6.7 Hz, 1 H) 8.94 - 9.08 (m, 1 H) 9.21 (d, J=6.2 Hz, 1 H) 9.45 (s, 1 H).

[00182] Example 1 1 : 1.3 g nicotinamide-3-D-ribofuranosidebromide (3.88 mmol; 1 eq) was dissolved in 5 mL water and filtered through 40 g H ₂ S0 ₄ -activated ion exchange resin, washed with 150 ml_ water and lyophilized to afford 1.27 g nicotinamide^-D- ribofuranoside sulfate (3.62 mmol, 93 %) as a white solid.

[00183] Bromide content (IC): 0.0 %; Sulfate content (IC): 13.0 %

¹ H-NMR (400 MHz, D ₂ 0) d ppm 3.83 (dd, J=13.0, 3.6 Hz, 1 H) 3.91 - 4.02 (m, 1 H) 4.25 - 4.34 (m, 1 H) 4.36 - 4.41 (m, 1 H) 4.46 (t, J=4.7 Hz, 1 H) 6.20 (d, J=4.4 Hz, 1 H) 8.24 (t, J=6.9 Hz, 1 H) 8.93 (d, J=8.3 Hz, 1 H) 9.23 (d, J=6.2 Hz, 1 H) 9.53 (s, 1 H).

[00184] Example 12: 1.3 g nicotinamide^-D-ribofuranoside bromide (3.88 mmol; 1 eq) was dissolved in 5 ml_ water and filtered through 40 g H ₃ P0 ₄ -activated ion exchange resin, washed with 150 ml_ water and lyophilized to afford 1.42 g nicotinamide- b-D- ribofuranoside dihydrogen phosphate (4.16 mmol, 104 %; containing 10 % water) as a white solid.

[00185] Bromide content (IC): 0.0 %; Phosphate content (IC): 20.8 %

¹ H NMR (400 MHz, D ₂ 0) d ppm 3.81 (dd, J=13.0, 3.6 Hz, 1 H) 3.96 (dd, J=13.0, 2.8 Hz, 1 H) 4.21 - 4.33 (m, 1 H) 4.39 (d, J=3.9 Hz, 1 H) 4.43 (t, J=4.7 Hz, 1 H) 6.16 (d, J=4.6 Hz, 1 H) 8.20 (t, J=6.9 Hz, 1 H) 8.89 (d, J=7.7 Hz, 1 H) 9.19 (d, J=6.3 Hz, 1 H) 9.51 (s, 1 H).

Example 13 to 17: Compositions with pullulan

[00186] Examples 13 and 14: Stock solutions of pullulan and nicotinamide b-D- ribofuranoside chloride prepared according to the methods of the invention were mixed in the following ratios:

- Example 13: 1.8 ml_ of an aqueous pullulan solution (120 mg/ml) was mixed with 0.050 mL of an aqueous solution of nicotinamide b-D-ribofuranoside chloride (200 mg/ml_)

- Example 14: 4 mL of an aqueous pullulan solution (120 mg/ml) was mixed with 0.050 mL of an aqueous solution of nicotinamide b-D-ribofuranoside chloride (200 mg/mL); from both solutions were 0.4 mL aliquots pipetted on a solid surface and let dried at 21 °C and 30% room humidity for 15 hours to obtain amorphous, glassy, hard lens shaped pullulan nicotinamide b-D-ribofuranoside chloride tablet. [00187] Examples 15 to 17: Nicotinamide b-D-ribofuranoside chloride was added to a solution of pullulan (5 mg/mL) in water. The reaction mixture was homogenized with ultrasound for 5 minutes and lyophilized overnight to yield the specific nicotinamide b-D- ribofuranoside chloride-pullulan-complexes as white solids. The white solids were amorphous as was shown by XRD analyses due to the absence of sharp diffraction peaks. Example 15: 250 mg pullulan; 250 mg nicotinamide b-D-ribofuranoside chloride. Example 16: 500 mg pullulan; 250 mg nicotinamide b-D-ribofuranoside chloride. Example 17: 1.2 g pullulan; 250 mg nicotinamide b-D-ribofuranoside chloride.

Example 18: Preparation of thionicotinamide- -D-ribofuranoside chloride (a compound of formula S-lb)

[00188] 15 g of thionicotinamide^-D-ribofuranoside bromide S-la from Example 6 were dissolved in 80 ml water. 66 g of ion exchange resin Amberlite IRA-402 (Cl-Form) were added to the orange-yellow solution and stirred for half an hour. The resin was removed by filtration and washed with 150 ml water in three portions. To the filtrate were added 66 g of ion exchange resin, again stirred for half an hour, filtered and washed with 150 ml water in three portions. This exchange was repeated further three times using 66 g of ion exchanger each. The final filtrate was evaporated to give 14.7 g of a clear, orange-yellow oil. This oil was dissolved in 30 ml methanol and put in the refrigerator, whereby some crystals formed overnight. The next day crystallization was completed by stirring in an ice bath and diluting the thick yellow suspension with a mixture of 45 ml methanol and 75 ml ethanol. The product was filtered, washed with ethanol several times and dried to give 6.7 g (51 %) of the title compound as bright yellow crystals. The bromide content (IC) was below 0.1 %. Mp: 1 17 °C.

From the mother liquor further 3.63 g (28 %) of yellow crystals were isolated. Mp: 1 16°C.

1H-NMR (400 MHz, D ₂ 0): 3.85 (dd, 1 H, H5’), 3.99 (dd, 1 H, H5’), 4.31 (t, 1 H, H3’), 4.40- 4.50 (m, 2H, H4’, H2’), 6.18 (d, 1 H, H1’), 8.16 (t, 1 H, H5), 8.84 (d, 1 H, H4), 9.14 (d, 1 H, H6), 9.61 (s, 1 H, H2);

¹³ C-NMR (100 MHz, D ₂ 0): 60.2 (C5‘), 69.7 (C3‘), 77.4 (C2‘), 87.6 (C4‘), 100.0 (C1‘), 128.0 (C5), 139.6 (C3), 139.9 (C2), 141.7 (C6), 143.9 (C4), 194.6 (CSNH2). Example 19: Preparation of thionicotinamide-2,3,5-tri-0-acetyl- -D-ribofuranoside chloride (a compound of formula S-Vb)

[00189] 10 g of thionicotinamide-2,3,5-tri-0-acetyl-3-D-ribofuranoside bromide S-Va from Example 5 were dissolved in 50 ml water. 44 g of ion exchange resin Amberlite IRA-402 (Cl-Form) were added to the orange-yellow solution and stirred for half an hour. The resin was removed by filtration and washed with 100 ml water in two portions. To the filtrate were added 44 g of ion exchange resin, again stirred for half an hour, filtered and washed with 100 ml water in two portions. This exchange was repeated further three times using 44 g of ion exchanger each. The final filtrate was evaporated to give 9.6 g of an orange-yellow resin. Most of the resin dissolved in 20 ml ethanol and soon after a bright yellow precipitate was formed. The rest of the resin crystallized while stirring with further 30 ml ethanol for one hour at 40 °C. The suspension was stored overnight at 5°C. 20 ml isopropanol were added and the yellow suspension stirred once more for an hour at 5 °C. The product was filtered, washed several times with isopropanol and dried to give 8.8 g (90 %) of the title compound as a yellow crystalline powder. The bromide content (IC) was below 0.1 %. Mp: 138 °C.

¹ H-NMR (400 MHz, DMSO-d6): 2.07 (s, 3H), 2.1 1 (s, 3H), 2.14 (s, 3H) 4.47 (m, 2H, H5’), 4.70 (m, 1 H, H4’), 5.47 (t, 1 H, H3’), 5.69 (dd, 1 H, H2’), 6.71 (d, 1 H, H1’), 8.31 (dd, 1 H, H5), 9.14 (d, 1 H, H4), 9.27 (d, 1 H, H6), 9.63 (s, 1 H, H2), 10.70 (s, 1 H, NH), 10.88 (s, 1 H, NH);

¹³ C-NMR (100 MHz, DMSO-d6): 20.8, 20.9, 21.1 , 62.9 (C5‘), 69.6 (C3‘), 75.7 (C2‘), 82.6 (C4‘), 97.6 (C1‘), 127.9 (C5), 138.8 (C3), 141.0 (C2), 142.8 (C6), 145.3 (C4), 192.7 (CSNH2), 169.7, 169.9, 170.5.