The synthesis of combinatorial compound libraries is rapidly taking on the role of a powerful component within modern lead finding processes that aim at the identification of compounds with novel target activities of interest. In the drug discovery context, the ability to synthesize small organic molecules with high yield on a solid support has a definite strategic relevance. It facilitates the preparation of compound arrays in multiple parallel syntheses and enables the application of combinatorial methods for the synthesis of large libraries suitable for systematic evaluations in biochemical or biological test systems. In view of the expected biostability and bioavailability, small organics (e.g. heterocycles) rather than chain-like biooligomers are more attractive leads for subsequent medicinal chemistry efforts.

Here we report a scope and limitation study on a reaction sequence on solid phase, suitable for the generation of molecular diversity on small heterocycles. For each reaction, suitable conditions on solid phase were worked out and a variety of reactive agents (building blocks) was utilized in an effort to grasp the system's breadth of applicability. The inventive reaction sequence can be applied, for example, to exploit the combinatorial approaches of the split and mix concept. Surprisingly, using the inventive method a new facile way for the synthesis of combinatorial compound libraries consisting of modified heterocyclic rings in high yields and purity is provided. These combinatorial compound libraries serve as valuable reservoirs for the screening for pharmaceutically active compounds.

Detailed description of the invention

The current invention concerns a process of solid phase synthesis of a heterocyclic ring, characterized in that it comprises the following steps a) a solid carrier having reactive surface groups is loaded directly or via a spacer group with a compound bearing an aldehyde or a methylketone function, b) said function is modified using the Wittig reaction or the aldol condensation, c) the heterocyclic ring is closed using a compound comprising two nucleophiles, wherein at least one of said nucleophiles is NH ₂ .

In a preferred embodiment of the invention in step a) the compound bearing an aldehyde or a methylketone function is of formula 1 or 2

HOOC _R1 ⁽²⁾ wherein:

R ^1a or R ^1b is arylene, X-aryl, aryl-Y, X-aryl-Y, wherein X and Y are the same or different and are selected from the group consisting of C-ι-C ₁₀ alkylene, OCrCι ₆ alkylene with preference given to OCrC ₁₀ alkylene, C ₂ -C ₁₀ alkenylene and OC ₂ -Cι ₀ alkenylene; wherein the X and Y group may be unsubstituted or substituted by bromo, chloro, fluoro, nitro, methoxy or ethoxy, and wherein aryl and arylene are as defined below. Suitable X and Y groups independent of one another are, for example, CH ₂ , C ₂ H ₂₎ OCH ₂ , OCH ₂ CH ₂₎

In a preferred embodiment of the invention R ^1a is arylene, X-aryl, aryl-Y, or X-aryl-Y, wherein X and Y are the same or different and are selected from the group consisting of C C ₄ alkylene and Od-C ₄ alkylene; wherein the X and Y group may be unsubstituted or substituted by bromo, chloro, fluoro, nitro, methoxy or ethoxy, and wherein aryl and arylene are as defined below. Suitable X and Y groups are, for example, CH ₂ , C ₂ H ₂ , OCH ₂ , and OCH ₂ CH ₂ . In a more preferred embodiment of the invention R ^1a is phenylene,

furanylene, thienylene, 1 -methyl-pyrrolylene or

R ^1b preferably is arylene or X-aryl, wherein X is CrCι ₀ alkylene, OC Cι ₀ alkylene, C ₂ -C ₁₀ alkenylene or OC ₂ -C ₁₀ alkenylene unsubstituted or substituted by bromo, chloro, fluoro, nitro, methoxy or ethoxy, and wherein aryl and arylene are as defiend below. Suitable X groups are, for example, (CH ₂ ) _1-4 , (C H ₂ )ι^O, CH=CH(CH ₂ )ι-4, o r CH=CH(CH ₂ ) ₁ - ₄ θ. In a more preferred embodiment of the invention, R ^1b is phenylene, biphenylene, pyrrolylene,

In another preferred embodiment of the invention in step b) the reagent for the Wittig reaction is of formula 3 and the reagent for the aldol condensation is of formula 4 or 5

wherein:

R ² is unsubstituted or substituted aryl, XH, X-aryl, aryl-Y, or X-aryl-Y, wherein X and Y are the same or different and are selected from the group consisting of C Cι ₀ alkyiene, C ₂ -Cι ₀ alkenylene and C ₂ -Cι ₀ alkinylene, and wherein aryl is as defined below.

In case of formula 3, in a preferred embodiment R ² is Cι-C ₄ alkyl, CrC ₄ alkenyl, or C C ₄ alkinyl, unsubstituted or substituted with fluoro, chloro, or bromo, or R ² is aryl wherein aryl is as defined below. In a more preferred embodiment R ² of formula 3 is C ₁ -C ₄ alkyl, phenyl, naphthyl, 4-NO ₂ C ₆ H ₄₎ 2,4-(NO ₂ ) ₂ C ₆ H ₃ , 2,4-CI ₂ C ₆ H _3l 2,4-(CH3) ₂ C6H ₃₎ 2,4- (CH ₃ O) ₂ C ₆ H ₃ , 4-CH ₃ OC ₆ H ₄ , 2-CIC ₆ H ₄ , thienyl, pyrrolyl or pyrazinyl.

In case of formula 4, R ² is aryl, wherein aryl is as defined below; more preferred is phenyl, naphthyl, biphenyl, thienyl, furyl, quinolyl, pyridinyl, pyrrolyl or pyrazinyl unsubstituted or substituted with nitro, methoxy, ethoxy, bromo, chloro, fluoro, methyl or ethyl. In an even more preferred embodiment R ² is phenyl, naphthyl, 4-NO ₂ C ₆ H ₄ , 2,4-(NO ₂ ) ₂ C ₆ H ₃ , 2,4- CI ₂ C ₆ H ₃ , 2,4-(CH ₃ ) ₂ C ₆ H ₃ , 2,4-(CH ₃ O) ₂ C ₆ H ₃ , 4-CH ₃ OC ₆ H ₄₎ 2-CIC ₆ H ₄ , thienyl, pyrrolyl, pyrazinyl or ethylpyrazinyl.

In case of formula 5, R ² is aryl, or unsubstituted or substituted aryl-Y, wherein aryl is as defined below, and wherein Y is selected from the group consisting of Cι-Cι ₀ alkylene, C ₂ -C ₁₀ alkenylene and C ₂ -C ₁₀ alkinylene. In a preferred embodiment thereof, R ² is aryl, wherein aryl is as defined below; more preferred is phenyl, naphthyl, thienyl, pyridinyl, pyrrolyl or pyrazinyl unsubstituted or substituted with nitro, chloro, fluoro, methyl or ethyl. In an even more preferred embodiment thereof, R ² is phenyl, naphthyl, 4-NO ₂ C ₆ H , 2,4- (NO ₂ ) ₂ C ₆ H ₃ , 2,4-CI ₂ C ₆ H ₃ , 2,4-(CH ₃ ) ₂ C ₆ H ₃ , 2,4-(CH ₃ O) ₂ C ₆ H ₃ , 4-CH ₃ OC ₆ H ₄ , 2-CIC ₆ H ₄ , thienyl, pyrrolyl, pyrazinyl or ethylpyrazinyl, propyl or isopropyl.

A preferred R ³ is hydrogen, d-Cioalkyl, C Cι ₀ alkenyl and C Cι ₀ alkinyl; preferred is hydrogen, methyl or ethyl.

ln another preferred embodiment of the invention in step c) the nucleophile is of formula 6, 7, 8, 9, 10 or 10a

₄ j? (6), R ⁵ (7), R ⁷ (8), _Rβ (9) , < ¹ °)

^{I π} 2 M HNNI K NIMH„ V 'MNUL U HMN —- KNIMH, M H ₂ MN K NllH,

(10a)

H ₂ N NH ₂ wherein

R ⁴ is a residue that does not interfere with the ring-closure; preferred is aryl, -X, -OX, - COX, CONHX, CONH ₂ , CONHaryl, or -NO ₂ wherein X is C C ₁₀ alkyl or C ₂ -C ₁₀ alkenyl which is unsubstituted or substituted with fluoro, chloro, bromo, iodo, nitro, methoxy, ethoxy, methyl, ethyl, propyl or i-propyl; more preferred is COC C ₄ alkyI, CONHd- C ₄ alkyl, CN and CONHaryl; even more preferred is CONH ₂₎ CN;

R ⁵ is a residue that does not interfere with the ring-closure; preferred is aryl, adamantyl, morpholino, -X, -COX, -NH ₂ , -NHY, -NX ₂ , C ₃ -C ₇ cycloalkyl, aryl or -XOaryl unsubstituted or substituted with fluoro, chloro, bromo, iodo, nitro, carbamoyl, methoxy, ethoxy, methyl, ethyl, propyl, i-propyl or CF _3l wherein X is Cι-Cιoalkyl or C ₂ -Cι ₀ alkenyl, and wherein Y is C doalkyl, C ₂ -C ₁₀ alkenyl, aryl-NH-C(NH)-NH-, ZOOC-CH(NH ₂ )-d-C ₄ alkyl-NH-, ZOOC- CH(NH(CO-phenyl))-d-C ₄ alkyl-NH- or ZOOC-CH(OH)-d-C ₄ alkyl-NH-, wherein Z is H, aryl or C C alkyl; more preferred is 2,4-(CH ₃ O) ₂ C ₆ H ₃ , 2,4-CI ₂ C ₆ H ₃ , phenyl, pyrrolyl, pyrazinyl, thienyl, 4-CH ₃ OC ₆ H ₄ , cyclopropyl, pyridyl, isothiazolyl, methyl-isothiazolyl, t- butyl, methyl, trifluoromethyl, amino, -CH ₂ CH ₂ CONH ₂ , -CH ₂ OC ₆ H ₅ , phenyl-NH-C(NH)- N H - , H O O C -CH(NH ₂ )-(CH ₂ ) ₃ - N H - , H O O C -CH(NH(CO-phenyl))-(CH ₂ ) ₃ - N H - , o r HOOC-CH(OH)-(CH ₂ ) ₃ -NH-;

R ⁶ is a residue that does not interfere with the ring-closure; preferred is COCH ₃ , COCH ₂ CH ₃ , COOCH ₃ , COCH ₂ CH ₃ , C N , S O ₂ C C ₄ alkyl, SO ₂ aryl, and NO ₂ ; more preferred is CN, COCH ₂ CH ₃ , or COCH ₃ ;

R ⁷ is a residue that does not inter ere with the ring-closure; preferred is hydrogen, d- C ₁₀ alkyl, CF ₃ , and aryl; more preferred is d-C ₄ alkyl, CF ₃ , and aryl; even more preferred is methyl;

R ⁸ is a residue that does not interfere with the ring-closure; preferred is Cι-C ₄ alkyl, unsubstituted or substituted with halogen NO ₂ , CN, OH or NH ₂ , and aryl; more preferred is phenyl;

R ⁹ is a residue that does not interfere with the ring-closure; preferred is aryl, pyridyl,

thienyl, purinyl, and unsubstituted or substituted with fluoro, chloro, bromo, iodo, nitro, C C ₄ alkyl, CF _3| COOCH ₃ , OCH ₃ or OCH ₂ CH ₃ ; more preferred is diaminopyridyl, thienyl, purinyl, and phenyl: and wherein aryl is as defined below.

Further preference is given to a solid phase synthesis according to the present invention, wherein in step c) a nucleophile of formula 10 is used

(10)

&

H ₂ N NH ₂

wherein R ⁹ is as defined above, inclusive the respective preferences.

Within the context of the present invention, and if not specified otherwise, suitable aryl groups are, for example, thienyl, pyrrolyl, indolyl, thiantrenyl, furyl, phenoxanthiinyl, benzofuranyl, isobenzofuranyl, pyrazolyl, isothiazolyl, isoxazolyl, pyridinyl, pyrazinyl, pyrimidyl, indolizinyl, indazolyl, isoquinolyl, quinolyl, phthalazinyl, stilbenyl, naphthyridinyl, quinoxalinyl, quinazolyl, cinnolinyl, phenyl, naphthyl, anthranyl and phenanthranyl; wherein these groups are unsubstituted or substituted by groups like fluoro, chloro, bromo, nitro, methoxy, ethoxy, methyl, ethyl, propyl, isopropyl, hydroxy, phenyl, phenoxy, SCH ₃ , CF ₃ or CN, of which fluoro, chloro, bromo, nitro, methoxy or ethoxy are preferred. Suitable arylene groups are derived from the respective aryl groups as specified above.

Preferred examples for the claimed reactions are given in the reaction schemes below

,N resin'

wherein the variables R ,1 ^ι a ^a , r R-)1 ¹ b ^D , and R ² to R ⁹ are as defined herein, inclusive the respective preferences;

and in the case of the synthesis of benzodiazepines, which constitutes a preferred embodiment of the present invention, further modifications are possible and useful. These additional modification steps are also part of the invention, and are exemplified as follows:

wherein

R ¹⁰ is d-C ₁₀ alkyl unsubstituted or substituted with fluoro, chloro, bromo, nitro, methoxy, ethoxy, methyl, ethyl, propyl or isopropyl, or aryl; preferred is d-C ₄ alkyl unsubstituted or substituted with fluoro, chloro, bromo, nitro, methoxy, ethoxy, methyl, ethyl, propyl or isopropyl; more preferred is t-butyl and CF ₃ ; R ¹¹ is d-dalkyl, C C ₄ alkylCOCH ₂₎ CH ₂ =CH-CH ₂ , aryl COCH _2l or CNCH ₂ ; preferred is methyl and ethyl;

»12

R ¹ * is C ₂ -C ₆ alkyl S ^" ;

R is aryl; preferred is phenyl;

R ¹⁴ is aryl; preferred is phenyl;

R ¹⁵ is aryl; preferred is phenyl;

R ¹⁶ is COOCι-C ₄ alkyl, d-doalkyl, unsubstituted or substituted with fluoro, chloro, bromo, nitro, methoxy, ethoxy, methyl, ethyl, propyl or isopropyl, or aryl; preferred is d-C ₄ alkyl unsubstituted or substituted with fluoro, chloro, bromo, nitro, methoxy, ethoxy, methyl, ethyl, propyl, isopropyl, COOCH ₃ , COOCH ₂ CH ₃ or CH ₃ ; more preferred is COOCH ₃ , COOCH ₂ CH ₃ and CH ₃ ; and wherein aryl is as defined above.

Such reaction steps leading to compounds nos. 11 to 19, respectively, are a preferred embodiment of the present invention.

The resulting compounds can be released from the solid carrier for example by using the following reaction step:

H I .NL 20% TFA CHpC H.NL ^' resin^ »

O O

Usually the solid carrier is a particle that is insoluble in the reaction media and to which the ligand can be bound in sufficient amount by means of reactive groups at the surface of the particle. In a preferred embodiment of the invention the solid carrier comprises a resin, e.g. polystyrene.

The binding of a target compound to the solid carrier is effected, e.g. by a linker bearing a amino, carboxyl, hydroxyl, halogen or silyl group. These reactive groups are usually already constituents of the solid carrier, but they can also be applied or modified subsequently. The solid carrier customarily employed in solid-phase synthesis can be used, for example those used in errifield peptide synthesis. They consist largely of a polystyrene molecule that is crosslinked by copolymerization with divinyl benzene. The molecules are additionally derivatized to attach the reactants in the solid-phase synthesis. Preferred is a solid carrier comprising a resin, in particular polystyrene, having attached thereto the Rink amide linker (H. Rink, Tetrahedron Lett. (1987), 28, 3787).

The inventive solid phase synthesis can be used for the generation of combinatorial compound libraries, e.g., in a the split and mix concept (Furka et al., Abstr. 14th Int. Congr. Biochem., Prague (1988), 5, 47; Furka et al., Int. J. Peptide Protein Res. (1991), 37, 487). The inventive libraries may also be synthesized using taging methods in order to analyze the structure of a hit after screening suitable tagging methods are generally known and are described, for example in WO-9306121 and WO-9408051.

Also embraced by the scope of the invention is the combinatorial compound library obtainable by said method.

Another embodiment of the invention is the use of the inventive solid phase synthesis for the simultaneous synthesis of several single compounds, for example using an array of pins, microtiter plates and the like.

General method for the synthesis:

Step a)

For example, in a first reaction step, the solid carrier is loaded with a carboxylic acid bearing an aldehyde or a methylketone function. The carbonyl group of the added compound is activated by standard methods and anchored, e.g., to the acid labile Rink amide linker on polystyrene (Rink, Tetrahedron Lett. (1987), 28, 3787). 4-(2',4'-Dimethoxyphenyl-fmoc-aminomethyl)phenoxy resin (Rink amide resin) is subjected to repeated washes with about 20% piperidine/DMA until no UV absorption from Fmoc is detected in the eluate. Than the NH2-Nnker group is acylated with about 3 eq of acetyl carboxylic acid at RT (preactivation with about 3.3 eq DICD and about 3.3 eq HOBt) until the Kaiser test (Kaiser et al., Anal. Biochem. (1970), 34, 595) is negative.

Step b)

In a second reaction step an α, β-unsaturated carbonyl group is introduced by a) applying an aldol condensation to the aldehyde group, e.g., by treating the methyl ketone group with anhydrous dioxane, adding LiOH and a suitable aldehyde, as defined above; or

b) applying the Wittig reaction to the mehtylketone group, e.g., by treating the resin bound aldehyde group with a triphenyl phosphine as defined above in DMA. Other suitable conditions for these chemical reactions are generally known and are performed routinely, e.g. the Wadsworth-Emmons reaction. Step c)

In a third reaction step a ring is closed by reacting the α, β-unsaturated carbonyl group with a compound comprising two nucleophiles, wherein at least one of said nucleophiles is NH ₂ .

The compounds are chemically cleaved from the support according to known methods. For example, if the Rink amide linker is used, cleavage from the support is done by treatment with about 20% v/v TFA/CH ₂ CI ₂ (Rink, Tetrahedron Lett. (1987), 28, 3787).

Also embraced by the scope of the invention is a method for the preparation of a combinatorial compound library comprising, for example, the reaction steps as described above, inclusive the respective preferences, wherein optionally before a reaction step is carried out, a) the resin pool is divided into different portions, b) said reaction step is carried out in each portion using a different chemical compound or reaction, and c) the portions are mixed together.

In order to synthesize a combinatorial compound library, e.g. according to Houghten et al. Nature (1991) 354, 84-86; a solid carrier having reactive surface groups is loaded directly or via a spacer group with a compound bearing an aldehyde or a methylketone function; or the resin is divided first into several portions then each portion is loaded directly or via a spacer group with a different compound bearing an aldehyde or a methylketone function and mixed again. Afterwards, if necessary, the pool containing the modified resin is divided into several separate portions again. The Wittig reaction or the aldol condensation is carried out in each portion using a different reagent to get different compounds. These separated pools are mixed and, if appropriate, divided again into several separate portions in which the heterocyclic ring is closed using a compound comprising two nucleophiles, as defined above and, afterwards, the separated pools are

mixed again. If desired, the mixture may be divided into several separate portions again for carrying out one or more further modifications in common or to generate a further diversity of the library. After mixing, a combinatorial compound library has been created that is suitable, e.g., for screening.

Especially in the case of benzodiazepines further modifications are suitable to increase the variability of the substitution schemes of the individual compounds of the library.

In order to avoid side effects the inventive library can be cleaved from the resin before or after screening. Methods for the identification of the inventive compounds are generally known. For example, such methods are based on tagging or sequential unrandomization, or on microanalytical technologies, like cleavage of single beads and mass spectrometry identification.

Accordingly, a further embodiment of the invention comprises a compound library produced with or obtainable by the inventive method, inclusive the respective preferences thereof, and the use of this compound library, especially for screening purpose.

The following examples are given for illustrative purposes without limitation and refer to preferred embodiments of the present invention.

Experimental Part

Abbreviations:

HOBt = 1 -hydroxybenzotriazole

DICD = diisopropylcarbodiimide

DMA = dimethylacetamide

DMF = dimethylformamide

Fmoc = fluorenylmethyloxycarbonyl

TFA = trifluoroacetic acid

THF = tetrahydrofuran

General Methods

HPLC(I) analytical separation is achieved using a reverse phase purospher rp-18 5μ 125 mm x 4 mm column, 215 nm, 5-100% CH ₃ CN/0.1% TFA over 20 min, 1 ml/min. A part of the eluate (split 1 :25) is introduced into a Quattro-BQ mass spectrometer (VG Biotech, Altrincham, England), operated at a source temperature of 60°C and a cone voltage of 50 V, via an electrospray interface (El). The mass range from 100 to 800 Dalton is scanned in 4 seconds.

HPLC(II) analytical separation is achieved using a reverse phase nucleosil C18 5 μ 250 mm x 4.6 mm column, 215 nm, 10-90% CH ₃ CN/0.1% TFA over 30 min, 1 ml/min.

HPLC(III) analytical separation is achieved using the same conditions as described for HPLC(II), however, the gradient is run for 10 min.

Kaiser test is performed as described in Kaiser et al., Anal. Biochem. (1970), 34, 595.

Example 1 : Preparation of a compound of formula e1

5g (2.25 mmol) 4-(2',4'-Dimethoxyphenyl-fmoc-aminomethyl)phenoxy resin (Rink amide resin) is subjected to repeated washes with 20% piperidine/DMA until no UV absorption from Fmoc is detected in the eluate, followed by 5 washes with DMA. The NH ₂ -linker group is acylated with 22.5 ml of a 0.3M-solution of 4-carboxybenzaldehyde (6.75 mmol) at r.t. (preactivation 40 min with 3.3 eq DICD (7.23 mmol) and 3.3 eq HOBt (7.23 mol)) until the Kaiser test is negative.

Example 2: Preparation of a compound of formula e3

(e3)

5g (2.25 mmol) 4-(2',4'-Dimethoxyphenyl-fmoc-aminomethyl)phenoxy resin (Rink amide resin) is subjected to repeated washes with 20% piperidine/DMA until no UV absorption from Fmoc is detected in the eluate, followed by 5 washes with DMA. The NH ₂ -linker group is acylated with 22.5 ml of a 0.3 M-solution of acetophenone-4-carboxylic acid (6.75 mmol) at r.t. (preactivation 40 min with 3.3 eq DICD (7.23 mmol) and 3.3 eq HOBt (7.23 mol)) until the Kaiser test is negative.

Example 3: Preparation of compounds of formulae e2a -e2i

To a 4 ml glass vial containing 50.0 mg the compound of formula e1 on Rink amide resin (19.7 μmol) in 1.6 ml anhydrous DME is added 16.5 mg of LiOH-H ₂ O (394 μmol) and 394 μ mol of the appropriate methylketone (R ₂ COCH ₃ ; see table 1). The vial is capped and shaken for 16 hours at room temperature. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and dried under high vacuum. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min affords chalcone derivatives of formulae e2a-e2i.

Table 1

X R ² purity Rf ) M X R ² purity Rf(l) M

2a CβHs 93 % 11.5 251 2f 2-NO ₂ C ₆ H ₄ 80 % 10.7 296

2b 2,4-(CH ₃ O) ₂ C ₆ H ₃ 94 % 1 1.6 311 2g 2-CIC ₆ H ₄ 83 % 11.8 285

2c 4-CH ₃ OC ₆ H ₄ 44 % 11.6 281 2h CH ₃ CH ₂ CH ₂ 18 % 10.2 217

2d ^« - 83 % 10.5 281 ^" 78 % 10.8 257 2i cχ

2e 100% 9.3 240

NH

Example 4: Preparation of compounds of formula e2a by Wittig reaction

23.6 ml of a 0.5 M solution of (5.91 mmol) in DMA is added to 2.00 g

(788 μmol) of the resin bound compound of formula e1 and the resulting mixture is shaken at 60°C for 14 hours. The resulting mixture is filtered, washed with DMA and i-PrOH and air dried in the filter. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min affords α, β-unsaturated ketone of formula e2a (see table 1 ; purity >95%, Rf(l)=11.5, M=251).

Example 5: Preparation of compounds of formula e2j by Wittig reaction

LI . pp _n 23.6 ml of a 0.5 M solution of ^^ ³ (5.91 mmol) in DMA is added to 2.00 g (788 μmol) of the resin bound compound of formula e1 and the resulting mixture is shaken at

60°C for 14 hours. The resulting mixture is filtered, washed with DMA and i-PrOH and air dried in the filter. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA CH ₂ CI ₂ for 15 min affords α, β-unsaturated ketone of formula e2j (see table 1 ; purity >95%, R<(l)=7.3,

M=189).

Example 6: Claisen-Schmidt reaction of immobilized methylketone To a 4 ml glass vial containing 50.0 mg of compound of formula e3 on Rink amide resin (20.2 μmol) in 1.6 ml anhydrous dioxane is added 17.0 mg of LiOH-H ₂ O (404 μmol) and 404 μmol of the appropriate aldehyde (R ₂ COH; see table 2). The vial is capped and shaken for 16 hours at room temperature. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and dried under high vacuum. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/ CH ₂ CI ₂ for 15 min affords chalcone derivatives of formulae e4a- e4g (see table 2).

Table 2:

X R ² purity Rf(l) M X R ² purity Rf(l) M a CβHβ 94 % 11.6 251 4e 2,4-CI ₂ C ₆ H ₃ 77 % 14.5 320 b naphthyl 79 % 13.7 301 4f 2,4-(CH ₃ O) ₂ C ₆ H ₃ 92 % 13.5 279 c 4-NO ₂ C ₆ H ₃ 89 % 11.9 296 4g i-propyl 49 % 10.7 217 d 2,4-(NO ₂ ) ₂ C ₆ H ₃ 36 % 10.7 341

Example 7: Cyclization to pyrimidines of formulae e5a-e5m

To a solution of the amidine hydrochloride (96 μmol, see table 3) in 96 μl DMA is added 96 μl of a 1 M suspension of NaOEt in DMA. Free amidines are used without treatment of NaOEt. The suspension is mixed by ultrasound for 5 min and centrifuged. The resultant solution is added to a the resin bound chalcone derivative e2a (9.6 μmol) in a reacti vial and the suspension is stirred under air atmosphere at 100°C over night. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and dried under high vacuum. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min affords pyrimidines of formulae e5a- e5m (see table 3).

Table 3

Example 8: Formation of pyrimidines e6a-e6d

To a solution of benzamidine hydrochloride (79 μmol) in 79 μl DMA is added 79 μl of a 1 M suspension of NaOEt in DMA. The suspension is mixed by ultrasound for 5 min and centrifuged. The resultant solution is added to the corresponding resin bound chalcone derivatives (7.9 mmol, see table 4) in a reacti vial and the suspension is stirred at 100°C over night under air atmosphere. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and dried under high vacuum. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/ CH ₂ CI ₂ for 15 min affords pyrimidines of formulae e6a-e6d (see table 4).

Table 4

X R ² purity Rf(l) M X R ² purity R.(i) M

6a 2,4-(CH ₃ O) ₂ C ₆ H ₃ >95 % 17.4 411 6c 2,4-CI ₂ C ₆ H ₃ >95 % 19.0 420

6b r >95 % 17.4 340 6d >95 % 16.0 381

⁽ X

Example 9: Formation of pyrimidines e7a-e7e

cr

To a solution of amidine hydrochloride ^H 2 ^{N NH} 2 (78 μmol, see table 5) in 78 μl DMA is added 78 μl of a 1 M suspension of NaOEt in DMA. The suspension is mixed by ultrasound for 5 min and centrifuged. The resultant solution is added to the resin bound

α, β-unsaturated ketone (7.8 μmol) and the suspension is

stirred at 100°C in a reacti vial over night under air atmosphere. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and dried under high vacuum. Cleavage of 3mg of resin with 800 μl 20 % v/v TFA/ CH ₂ CI ₂ for 15 min affords pyrimidines of formulae e7a-e7e (see table 5).

Table 5

X R ⁶ purity Rf(l) M X R ⁶ purity Rt(l) M

7a CβHs >95 % 26.4 289 7d NH ₂ >95 % 9.9 228

7b 4-CH ₃ OC ₆ H ₄ >95 % 25.4 319

7c >95 % 19.8 269 7e (x 291

Example 10; Synthesis of dihvdropyrimidinone e8a

To a 1.5 ml Eppendorf tube containing 4.7 mg (69 μmol) NaOEt in 276 μl anhydrous DMA is added 16.2 mg (6.9 μmol) resin loaded with compound of formula e2a and 5.1 mg (69 μmol) N-methyl urea. The reaction mixture is allowed to stand under Ar over night. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min yielded pyrimidinone of formula e8a (purity 90 %, R (l)=9.6, M=307).

Example 11 : Synthesis of dihvdropyrimidinone e8b

To a 1.5 ml Eppendorf tube containing 6.5 mg (96 μmol) NaOEt in 384 μl anhydrous DMA is added 20.0 mg (9.6 μmol) resin loaded with compound of formula e2a and 14.7 mg (96 μmol) benzyl urea. The reaction mixture is allowed to stand under Ar over night. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min yielded pyrimidinone of formula e8b (purity 90 %, R _f (ll)=24.9, M=383).

Example 12: Synthesis of pyridone of formula e9a

To a 1.5 ml Eppendorf tube containing 19.9 mg (177 μmol) potassium tert-butoxide in 355 μl anhydrous DMA is added 10.0 mg (4.0 μmol) resin loaded with the compound of formula e2a, 18.1 mg (177 μmol) of malonamide, and 23.7 mg (90 μmol) 18-crown-6. The

reaction mixture is allowed to stand under Ar for 4 hours. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min yielded pyridone of formula e9a (purity 60 %, R _f (ll)=16.3, M=335).

Example 13: Synthesis of pyridone of formula e9b

To a 1.5 ml Eppendorf tube containing 9.6 mg (86 μmol) potassium tert-butoxide in 171 μl anhydrous DMA is added 10.0 mg (4.0 μmol) resin loaded with the compound of formula e2a, (86 μmol) of 2-cyanoacetamide, and 14.4 mg (54 μmol) 18-crown-6. The reaction mixture is allowed to stand under Ar for 4 hours. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min yielded pyridones of formula e9b (purity 90 %, R (ll)=19.6, M=306).

Example 14: Synthesis of pyrazole of formula e10

To a 1.5 ml Eppendorf tube containing 10.0 mg of the compound of formula e2a on Rink amide resin (4.5 μmol) is added 450 μl 0.5M solution of phenylhydrazine in DMA. The reaction mixture is shaken for 16 hours at room temperature. The resin is washed with DMA and i-PrOH consecutively and air dried. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/ CH ₂ CI ₂ for 15 min affords pyrazole of formula e10 (purity 85 % one regioisomer,

Example 15: Synthesis of pyridines of formulas e11 a to e11 c (a) Synthesis of a pyridine of formula e11 a

To a 1.5 ml Eppendorf tube containing 20.0 mg of the compound of formula e2a on Rink amide resin (4.8 μmol) is added 350 μl acetonitrile and 10 mg (89 μmol) potassium tert- butoxide. The reaction mixture is sonicated for 50 min at room temperature under Ar and is allowed to stand over night. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min affords pyrazole of formula e1 1 a (purity >95 % , R _f (ll)=13.2, M=313).

(b) Synthesis of a dihydropyridine of formula e11 b

To a vial containing 15.5 mg (6.5 mmol) of the compound of formula e2a on Rink amide resin, 14.6 mg (132 mmol) 3-amino-2-cyclohexane-1 -one, 0.35 ml DMSO and 14.8 mg (132 mmol) tert. BuOK are added. The reaction mixture is shaken for 5 h at rt under Argon . The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. The product is cleaved from the resin with 20% (v/v) TFA/CH ₂ CI ₂ to afford dihydropyridine of formula e11 b (purity 72%, Rf(lll) =6.22, M=342).

(c) Synthesis of a pyridine of formula e11 c

A dry flask is charged with 2.76 mmol LDA and 10 ml THF at -78°C under N ₂ atmosphere, and a solution of diethyl methyl phosphonate (365 ml, 2.5 mmol) in 12.5 ml THF is added. After stirring for 1 h at -78°C, a solution of m-tolunitril in 5 ml THF is added. 1 ml of this reaction mixture is then added to a vial containing 10 mg (4.5 mmol) of the compound of formula e2a on Rink amide resin. The mixture is shaken for 14 h at rt under air atmosphere. The resin is washed with glacial acetic acid, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. The product is cleaved from the resin with 20% (v/v) TFA/CH ₂ CI ₂ to afford pyridine of formula e1 1c (purity 75%, Rf(lll) =8,95, M=364).

Example 16: Synthesis of a benzodiazepine of the formula e12

To a 5 ml glass vial containing 400 mg of the compound of formula e2a on a polyethylene glycol polystyrene based resin functionalized with the Rink linker (80 μmol) in 1 .6 ml anhydrous toluene is added 86.5 mg of ortho-Phenylenediamine (800 μmol) and 123 μl triethylamine (880 μmol). The vial is capped and shaken for 4 hours at 100°C. The resin is washed with H ₂ O, DMA, and i-PrOH consecutively and air dried. The resulting resin is again treated with the same amount of reagents for 16 hours at 100°C. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 5 min affords benzodiazepine of formula e12 (R,(ll)=17.1 , M=341).

Example 17: Acylation of the Benzodiazepin of formula e12

To a 1.5 ml Eppendorf tube containing 10.0 mg of the compound of formula e12 on Rink amide resin (4 μmol) is added a mixture of 5.9 μl acetylbromide (80 μmol) and 6.5 μl pyridine (80 μl) in DMA. The reaction mixture is standing for 2 hours at room temperature. The resin is washed with H ₂ O, DMA, i-PrOH and CH ₂ CI ₂ consecutively and air dried. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 5 min affords acetyl benzodiazepine of formula e13 (R _f (ll)=22.5, M=384).

Example 18: Synthesis of oxadiazolo benzodiazepines of formula e14

To a 5 ml reacti vial containing 20.0 mg of a compound of formula e13 on Rink amide resin (8 μmol) in 363 μl anhydrous toluene is added 8.7 μl of phenyl isocyanate (80 μmol), 2.9 μl nitroethane (40 μmol) and 11.2 μl triethylamine (80 μmol). The mixture is stirred for 5 hours at 100°C. The resin is washed with DMA, H ₂ O and i-PrOH consecutively and dried under high vacuum. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 15 min affords oxadiazolo benzodiazepines of formula e14 (regioisomers, R<(l)a=10.8, Rι(l)b=11.3, M=440).

Example 19: Synthesis of oxadiazolo benzodiazepines of formula e15

To a 5 ml reacti vial containing 20.0 mg of a compound of formula e13 on Rink amide resin (8 μmol) in 363 μl anhydrous toluene is added 8.7 μl of phenyl isocyanate (80 μmol), 4.4 μl ethyl nitroacetate (40 μmol) and 1 1 .2 μl triethylamine (80 μmol). The mixture is stirred for 5 hours at 1 00°C. The resin is washed with DMA, H ₂ O and i-PrOH consecutively and dried under high vacuum. Cleavage of 3 mg of resin with 800 μl 20 % v/v TFA/CH ₂ CI ₂ for 1 5 min affords oxadiazolo benzodiazepines of formula e1 5 (regioisomers, R,(l)a=12.3, R _f (l)b=12.6, M=498).