9-SUBSTITUTED PORPHYCENES

BACKGROUND OF THE INVENTION Field of the Invention:

The present invention concerns novel porphycene compounds and pharmaceutical compositions containing these compounds which are useful for therapeutic treatment of cancer and of dermatological diseases.

Discussion of the Background:

During the past few years there has developed a widespread recognition that modern, though sophisticated, cancer diagnosis and treatments have served neither to reduce the overall number of cases of reported cancers in the U.S.A. nor, save the notable cases, the death rate. This is a disheartening result for the billions of dollars invested in conquering the disease. Moreover, surgery, radiotherapy and chemotherapy are all associated with major debilitating side effects such as trauma, severe immunosuppression or toxicity which are not easily surmounted by patients already compromised by ill-health.

Systemically administered porphyrins localize preferentially in neoplasms of tumor-bearing animals (Policard, A., CR. Soc. Biol., 1924, 91:1423; Auler, H. and Banger, O., Z. Krebsforsch. , 1942, 53:65) . As a result, an ever-expanding effort has developed to employ porphyrinoid

dyes in cancer therapy. Recognition that this selective accumulation extends to many hyperproliferating cell types has also spurred interest in the use of porphyrinoid dyes in the photodynamic therapy of certain der atological diseases, cardiovascular medical problems, and endometrial proliferation.

Early work in the 1970's, followed by rapidly expanding studies in the 1980's, has shown that photodynamic therapy (PDT) offers a viable, less toxic and generally less painful approach to the treatment of cancer. PDT has been used to treat bladder, bronchial, bone marrow and skin tumors (Dougherty, Photochem. Photobiol., 1987, 45:879; Sieber et al., Leukemia Res., 1987, 11:43).

In such photodynamic therapy, porphyrinoid dyes are administered to a patient and are allowed to localize in neoplastic tissues (Lipson et al., J. Thoracic Cardiovascular Surgery, 1961, 42:623-629). Irradiation of the affected tissues with light at a wavelength which corresponds to an absorption band of the dye results in destruction of the neoplastic tissue (also see Kessel, D., "Methods in Porphyrin Photosensitization", Plenum Press, New York, 1985; Gomer, C. J., "Photodynamic Therapy", Pergammon Press, Oxford, 1987; and Doiron, D. R. and Gomer, C. J., "Porphyrin Localization and Treatment of Tumors", Liss, New York, 1984). The use of a fiber optic laser light source is described in U.S. 4,957,481. Dougherty et al. (Cancer Res., 1978, 38:2628; Photochem. Photobiol., 1987, 45:879) pioneered the field of PDT with the infusion of photoactivatable dyes, followed by the appropriate

long wavelength irradiation (600+ nm) of the tumors. Such irradiation generated a lethal shortlived species of oxygen which destroyed the neoplastic cells. Early experiments utilized a mixture that was termed hematoporphyrin derivative (HpD) . See also Lipson et al., J.N.C.I., 1961, 26:1;

Dougherty et al., J.N.C.I., 1975, 55:115; Diamond et al.. Lancet, 1972(11), 1175; D. Dolphin, "The Porphyrin", vol. I, Academic Press, New York, 1978; and D. Kessel, Photochem. Photobiol., 1984, 39:851. The deficiencies of HpD, especially prolonged phototoxicity caused by retained HpD components in human skin, led to its displacement by a purified fraction initially termed dihematoporphyrin ether (DHE) , and later marketed by QuadraLogics Technologies as the commercial product "PHOTOFRIN", which, although yielding improvements over HpD, nevertheless still suffered certain practical limitations. Known negative features of PHOTOFRIN and HpD include relatively weak absorption in the wavelength range above 600 nm, retention in dermal cells (potential source of phototoxicity) , only modest or low selectivity for tumor cells versus other cell types in vital organs, uncertain chemical composition of the mixtures and the inability to use available, modern, inexpensive diode lasers.

Characteristic of the earlier work in PDT and of "PHOTOFRIN" has been the use of complex mixtures of monomeric and polymeric porphyrinoids derived from processed blood constituents which were comprised of multiple components of indeterminate structure. Besides the obvious problems of

quality control in chemical analysis, at least one component of these mixtures accumulates and persists in cutaneous and/or subcutaneous tissues with the unfortunate side effect of delayed phototoxicity which can be severe. A great majority of the earlier PDT agents studied have been derived from natural sources (porphyrins, chlorins, purpurins, etc.) or from known chemicals originating in the dyestuffs industry (e.g., cyanine dyes) . For more recent PDT agents derived from natural sources, see U.S. 4,961,920 and U.S. 4,861,876. In animal and cell culture experiments, following PDT using porphyrinoid dyes, and depending upon the incubation time, damage to the vasculature, cell membranes, mitochondria and specific enzymes is observed. An increased selectivity for tumor cells can be obtained by injecting liposome encapsulated porphyrinoid sensitizers (Ricchelli and Jori,

Photochem. Photobiol., 1986, 44:151). Porphyrinoid dyes can be transported in the blood with the aid of lipoproteins such as low-density lipoprotein (Jori et al.. Cancer Lett., 1984, 24:291) . PDT has also been used to treat severe psoriasis (Diezel et al., Dermatol. Monatsschr., 1980, 166:793; Emtenstam et al., Lancet, 1989 (I), 1231). Treatment of viruses in transfused blood has also been reported (Matthews et al., Transfusion, 1988, 28:81; Sieber et al., Semin. Hematol., 1989, 26:35) .

Though not all cancers are candidates for PDT, those neoplasms of hollow organs and skin, including multifocal carcinoma in situ, which are sometimes inoperable and/or which

may not have a good track record for treatment by established therapeutic procedures, appear to be targets for PDT. Comprehensive coverage of photodynamic therapy has been provided by Henderson and Dougherty ("Photodynamic Therapy, Basic Principles and Clinical Applications", Henderson, B. . and Dougherty, T. J. , eds.; Marcel Dekker Inc., New York, Basel, Hong Kong, 1992).

Photodynamic therapeutically-induced tissue necrosis requires the simultaneous presence in or on cells of the photoactivatable dye, oxygen and light. The first widely-used PDT procedure, PUVA (psoralen with ultraviolet A light) , for treatment of psoriasis employs potentially harmful ultra¬ violet light. Red light transfers less energy to target tissues, is less dangerous, and penetrates more deeply into living tissues than does UV-A light. For these reasons, recent PDT research has focused on dyes absorbing strongly in the 600-750 nm wavelength range, of both natural and synthetic origin. Phthalocyanines, chlorins, purpurins and porphyrins are among the structural variants which have been studied in vitro and in vivo .

As the deficiencies of earlier PDT agents have become apparent, it has become possible to define activity parameters for and chemically synthesize improved, chemically pure, photoactivatable dyes for PDT therapy. The products of synthesis lend themselves more readily to further chemical structural manipulation than do the naturally occurring PDT agents which can be expensive and bear chemically sensitive constituents. The synthesis of novel porphycene macrocycles

embracing four pyrrole rings has been described by Vogel and coworkers. In 1986, Vogel and co-workers (Vogel, E. ; Kδcher, M. ; Schmickler, H.; and Lex, J. , Angew . Chem . , 98., 262 (1986); Angew . Chem . , Int . Ed . Engl . , 2.5, 257 (1986)) first published on the synthesis of a novel porphyrin (I) isomer with the parent structure named porphycene (II; R = L = H) .

(I) (ID

In the ensuing decade, the physical and biological properties of porphycenes have been described (see also U.S. Patent Nos. 4,913,907, 5,015,478, 5,132,101, 5,179,120, 5,244,671, 5,262,401, and 5,409,900) .

For PDT, the porphycenes offer clear advantages over clinically-evaluated mixed porphyrins. For example, chemically pure porphycenes may be easily prepared. Compositions containing porphycenes may be well-characterized and readily analyzed. Porphycenes absorb light of wavelengths above 600 nm far more strongly than porphyrins (e.g., by approximately an order of magnitude at 630 nm) . Porphycenes also rarely display the adverse phenomenon of molecular aggregation in therapeutically useful formulations, and show a

greater selectivity for accumulation in hyperproliferating cells.

The biological properties of two major series of porphycenes have been evaluated extensively: (1) the tetraalkylporphycenes (formula II, where R = alkyl, L = various substituents) and (2) the tetrakis(alkoxyalkyl)porphycenes (formula II, where R = alkoxyalkyl, L = various substituents; see Guardiano et al., Cancer Letters, 1989, 44, 1) . The 9, 10-ethylenic bridge (absent in porphyrins) has proven to be an excellent site for high yielding mono-substitution reactions, yielding porphycenes substituted at C-9 by hydroxyl, nitro, amino, halogen, esters, amides, imides, etc. Many of these C-9 substituted porphycenes exhibit the three-absorption maxima between 560 nm and 650 nm, with the strongest absorption typically at 635-645 nm (e _max = 30,000-50,000).

The alkoxyalkylporphycenes also exhibit unusually rapid cell penetration properties. These dyes in liposo es can be administered in vivo intravenously. A few minutes later, red light irradiation of tumorous tissues typically causes marked tumor necrosis (Richert, D.; Wessels, J.M.; Miiller, M. ; Kisters, M. ; Benninghaus, T. ; and Goetz, A.E., J. Med . Chem . , 37 , 2797 (1994)). Another demonstrated useful property is the penetration of (excised) human skin by a selected porphycene, thereby offering prospects of utility for alkoxyalkyl- substituted porphycenes in PDT of dermatological diseases (Landthaler, M. ; Szei ies, R.-M.; and co-workers at Department

of Dermatology, University of Regensburg; unpublished results) .

The porphycenes described above all show maximum light absorption below 650 nm which, though eminently suitable for PDT in dermatology, bladder carcinoma in situ, and certain cardiovascular conditions where tissue necrosis is desirably limited to 3-6 mm or less, are less suitable for the treatment of deeper seated lesions, as in many cancers. Furthermore, while lamps equipped with appropriate filters are available for dermatological use, irradiation of inner organs is more effectively addressed with laser light delivered via flexible fiber optic endoscopes. Earlier lasers, including tunable dye lasers, tend to be large and expensive pieces of equipment (requiring substantial space for installation) , and are sometimes unreliable for frequent use.

Replacement of tunable dye lasers by inexpensive diode array lasers is desirable for economic and other factors (e.g., reliability) . However, no commercially-available diode lasers offering 630-650 nm wavelengths are presently available. On the other hand, suitable diode lasers delivering light at ca. 680 nm are available.

Synthetic efforts have also focused on porphyrinoid compounds which are highly absorptive in the longer wavelength range of about 600-900 nm for use where the transparency of tissue is higher. Compounds such as purpurins (Morgan et al., J. Org. Che . , 1986, 51:1347; Morgan et al. , Cancer Res., 1987, 47:496; Morgan et al. , J. Med. Chem., 1989, 32:904; Hoober et al., Photochem. Photobiol., 1988, 48:579),

naphthocyanin silicon complexes (Firey et al., J. Am. Chem. Soc, 1988, 110:7626), chlorins (Robert et al., J.N.C.I., 1988, 80:330; Kessel, Cancer Res., 1986, 46:2248) , bacteriochlorins (Beams et al., Photochem. Photobiol., 1987, 46:639) and substituted phenylporphyrins (Kreimer-Birnbaum, Se in. Hematol., 1989, 26:157) have been prepared and tested in vivo . Additional PDT agents are described in EP 276,121. Pyrrole-containing ring systems larger than porphycene have also been prepared and evaluated as photosensitizers. Sessler et al. have prepared and studied texaphyrin (J. Am.

Chem. Soc, 1988, 110:5586) and Woodward et al. and Johnson et al. have prepared and investigated the sapphyrin ring system. Additionally, the platyrin system has been studied by LeGoff (Tetrahedron Lett., 1978, 4225; J. Org. Chem., 1987, 710) and vinylogous porphyrins have been studied by Franck (Angew. Chem., 1986, 98:1107; Angew. Chem. Int. Ed. Eng. , 1986, 25:1100; Angew. Chem., 1988, 100:1203; Angew. Chem. Int. Ed. Eng., 1988, 27:1170).

A need continues to exist, however, for new compounds for use in PDT therapy which are easily adaptable for use with commercial diode lasers, which have low intrinsic toxicity and high selective uptake in rapidly proliferating cells, which are efficient photosensitizers for singlet oxygen production, which are rapidly or at least moderately rapidly degraded and/or eliminated from the tissues after administration and which are available as chemically pure and stable compounds, easily subject to synthetic modification. Such desired

compounds should also be capable of formulation to allow transdermal delivery, if targeted for topical application.

SUMMARY OF THE INVENTION Accordingly, one object of the present invention is to provide new and effective compounds for use in photodynamic therapy of cancer and/or dermatological diseases whose properties and characteristics approach the ideal characteristics of PDT dyes listed above.

A further object of the present invention is to provide new and effective compounds and methods of PDT that are adaptable for use with commercially available diode lasers, especially those emitting light at about 680 nm.

A further object of the present invention is to provide novel compounds and methods for photodynamic therapy of tumors and/or lesions located deeper in tissues than those tumors and/or lesions currently treatable by PDT employing the earlier porphyrin mixtures HpD or DHE as the photoactivatable dyes.

A further object of the present invention is to provide new and effective compounds for use in PDT that are more stable than known 9-hydroxyporphycenes.

These and other objects of the present invention which will be readily understood in the context of the following detailed description of preferred embodiments have now been achieved with a novel family of porphycenes - the C-9 ethers. The present compounds have utility as PDT dyes for use in the

endometriosis macular degeneration, cardiovascular disease (e.g. prophylaxis of restenosis) and of dermatological diseases, i.e., psoriasis, etc., related problems.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention concerns porphycene ether compounds of the formula (III) :

wherein: each R is independently hydrogen, alkyl, aralkyl, aryl, alkoxyalkyl (e.g., a group of the formula -(CH^ _n OR ¹ , where n is an integer from 1 to 10 and R ¹ is alkyl, aralkyl or aryl) , aralkyloxyalkyl or aryloxyalkyl; and R ² is -CHR ³ R ⁴ or -(CH ₂ ) _m -Y, where: at least one of R ³ and R ⁴ is selected from the group consisting of C(0)OR ⁵ , C(0)R ⁵ , OC(0)OR ⁵ , C(0)NHR ⁵ , C(0)0 ^"

[NR ⁵ R ⁶ R ⁷ R ⁸ ] ⁺ , NHC(0)R ⁵ , NHC(0)0R ⁵ , NR ⁶ R ⁷ , NR ⁵ R ⁶ R ⁷⁺ A ^" , ZP(0) _p (R ⁵ ) ₂ , ZP(0) _p (OR ^s )R ⁵ , ZP(0) _p (OR ⁵ ) ₂ , ZS(0) _q R ⁵ , ZS(0) _q 0R ⁵ and ZS(O),N(R ⁵ ) ₂ , where p = 0-1, q = 0-2 and Z is a covalent bond, 0 or NR ⁵ , wherein:

R ⁵ , R ⁶ , R ⁷ and R ⁸ are independently hydrogen, alkyl, aryl, aralkyl, cycloalkyl or cycloalkylalkyl, or either or both of (i) R ⁶ and R ⁷ and (ii) R ^s and R ⁸ taken together with the nitrogen atom to which they are attached are a 3-7 membered saturated or unsaturated heterocyclic ring optionally containing an additional 0, NR ⁵ or S ring member, or when at least one of R ³ and R ⁴ is C(0)0R ⁵ , 0C(0)0R ⁵ , C(0)NHR ⁵ , NHC(0)R ⁵ or NHC(0)0R ⁵ , R ⁵ may comprise an amino acid, an oligopeptide, a monosaccharide or an oligosaccharide; and

A ^" is an anion; the other of R ³ and R ⁴ is independently a member of said group or is alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl or heterocyclyl; m = 1-20, more preferably 1-12, more preferably 1-4; and

Y is hydrogen, halogen, cyano, nitro, branched alkyl, straight-chain or branched alkoxy, aryl, aralkyl, cycloalkyl or heterocyclyl, C(0)R ⁵ , C(0)0R ⁵ , C(0)NHR ⁵ , C(0)0 ^" [NR ⁵ R ⁶ R ⁷ R ^Θ ]% 0C(0)0R ⁵ , NR ⁶ R ⁷ , NR ⁵ R ⁶ R ⁷⁺ A ^" , NHC(0)R ⁵ , NHC(0)0R ⁵ , ZP(0) _p (R ⁵ ) ₂ , ZP(0) _p (OR ⁵ )R ⁵ , ZP(0) _p (0R ^s ) ₂ , ZS(0) _q R ⁵ , ZS(0) _q 0R ⁵ or ZS(0) _q N(R ⁵ ) ₂ , wherein p, q, R ⁵ , R ⁶ , R ⁷ , R ⁸ , A ^" and Z are as defined above; or a salt thereof, with the proviso that when R ² is methoxymethyl, all four R groups are not simultaneously n- propyl, and when R ² is methyl, all four R groups are not simultaneously n-propyl or 2-methoxyethyl.

To improve water solubility, amino acids, oligopeptides, monosaccharides or oligosaccharides may be directly or indirectly bonded or tethered to the porphycene compounds. Amino acids, oligopeptides, monosaccharides and oligosaccharides may be directly bonded to the porphycene compounds by means of an ester, an amide or an ether linkage where said amino acid, oligopeptide, monosaccharide or oligosaccharide is incorporated in whole or in part as R ⁵ . Amino acids or oligopeptides may be indirectly tethered to the porphycene compounds through an alkylene, arylene or aralkylene linker unit to which the amino acid or oligopeptide is bonded through an ester or amide linkage. Similarly, glycosides may be indirectly bonded or tethered to the porphycene compounds through an alkylene, arylene or aralkylene linker unit to which the glycoside is bonded through an ether linkage at the C-l position of the sugar(s) (see U.S. 5,244,671, incorporated herein by reference).

Suitable alkyl groups within this invention are straight-chain or branched alkyl groups. Preferably, the alkyl groups have 1-20 carbon atoms, more preferably 1-12 carbon atoms. Examples include methyl, ethyl, n-propyl, i- propyl, n-butyl, iso-butyl, t-butyl, n-pentyl, hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, etc.

Suitable cycloalkyl groups include cycloalkyl groups having 3-7 ring atoms, preferably cyclopropyl, cyclopentyl, cyclohexyl and cycloheptyl groups. These cycloalkyl groups may be unsubstituted or may be substituted with one or more

alkyl substituents, generally from 1 to 3 alkyl groups having 1-6 carbon atoms.

Suitable cycloalkylalkyl groups include the cycloalkyl groups described above bonded to a straight-chain or branched alkylene group, preferably an alkylene group having 1-20 carbon atoms. In the present invention, "alkylene" refers to a divalent C ₁ -C ₂₀ saturated hydrocarbon diradical, similar to the definition of "alkyl" above.

Suitable heterocyclyl groups include saturated or unsaturated heterocyclyl groups having 3-7 ring atoms containing N, O, or S and, optionally, an additional N, O, or S ring member. Examples include oxiranyl, aziridinyl, thiazolyl, furyl, pyranyl, pyrrolyl, pyrrolidinyl, pyrrolinyl, piperidyl, pyridyl, thienyl, imidazolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, isothiazolyl, isoxazolyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, pyrazolinyl, piperazinyl, morpholinyl, etc.

Suitable aryl groups include C ₆ . ₂₀ carbocyclic aryl groups. Examples include phenyl, naphthyl, indenyl, etc. The aryl group may be optionally substituted, for example, with one or more _ ₆ alkyl, N0 ₂ , NR ₃ ⁺ A ^' , C(0)0" [NR ₃ ] ⁺ , C(0)0H, ZP0 ₃ H ₂ and/or ZSO _g H groups (where Z is as defined above and q = 1-3) , alkali and alkaline earth metal salts thereof, C^g alkyl esters thereof, etc. Arylene groups (C ₆ H ₄ ) may be ortho-, meta- or para-substituted, preferably para-substituted.

Suitable aralkyl groups are the aryl groups defined above bonded to a C _1-6 alkylene group. Examples include benzyl, phenylethyl, phenylpropyl, phenylbutyl, etc. The aralkyl

group may also include one or more substituents such as C _x _ ₆ alkyl, N0 ₂ , NR ₃ ⁺ A ^" , C(0)0 ^" [NR ₃ ]\ C(0)OH, ZP0 ₃ H ₂ and ZSO _g H (where Z is as defined above and q = 1-3) , alkali and alkaline earth metal salts thereof, C _ ₆ alkyl esters thereof, etc. Preferably, the aryl and aralkyl groups include at least one C(0)0 ^" or C(0)OH group.

Suitable amino acids include the 20 naturally occurring amino acids, i.e., phenylalanine, leucine, serine, tyrosine, alanine, glycine, cysteine, tryptophan, proline, histidine, arginine, glutamine, isoleucine, methionine, threonine, asparagine, lysine, valine, aspartic acid, glutamic acid, and non-naturally occurring synthetic amino acids. Suitable oligopeptides include two or more of these amino acids, preferably 2-10, more preferably 2-6 amino acids, bonded together through amide bonds.

Monosaccharides which may be bonded to the porphycene compounds of the present invention include both pentose and hexose saccharides including glucose, mannose, fructose, galactose, etc. Similarly, oligosaccharides containing a plurality of monosaccharide units, preferably 2-6 saccharide units, more preferably 2-3 saccharide units, including maltose, sucrose, lactose, etc., may be bonded or tethered to the porphycene compound, preferably through a sugar C-1 ether linkage. Particularly preferred compounds contain four identical R substituents. In even more preferred compounds, R is -(CH ₂ ) _n H or -(CH ₂ ) _rι OR ¹ , where R ¹ is C _1-6 alkyl and n is an integer from 1 to 6 (most preferably n-propyl or 2-methoxyethyl) .

Preferred substituents where R ² is -(CH ₂ ) _m -Y include those in which m = 1-6 (and more preferably, where m = 1) and Y is C ₆ H ₅ , where the phenyl group is substituted (preferably disubstituted, more preferably ortho- or eta- disubstituted) with -C(0)OR ⁵ (where R ⁵ is hydrogen or an alkyl group having 1-6 carbon atoms, more preferably where R ⁵ = H) . Preferred substituents where R ² is -CHR ³ R ⁴ include those in which R ³ and R ⁴ are each -C(0)OR ⁵ , where R ⁵ is hydrogen or a C _1-6 alkyl group (more preferably where R ⁵ = H) . The anion A ^" may be any anion (preferably any pharmaceutically acceptable anion) including, but not limited to, inorganic anions such as chloride, chlorate, perchlorate, sulfate, phosphate, diphosphate, bromate, bromide, iodide, permanganate and nitrate, and organic anions such as acetate, cyanide, benzoate, carbamate, bicarbonate, malate, maleate, fumarate, tartrate, succinate, citrate, lactate, methanesulfonate, p-toluenesulfonate, palmoate, salicylate and stearate.

The tetrasubstituted porphycenes are prepared by coupling appropriately substituted dialdehydes to form the porphycene ring structure. Further chemical modification of the four substituents gives various and suitable 2,7,12,17- tetrasubstituted porphycene starting materials (see U.S. 5,179,120 and U.S. 5,015,478, incorporated herein by reference in their entireties) .

Porphycene ether compounds of the present invention may be prepared by reacting a hydroxyporphycene having the formula (IV)

with an organic compound of the formula XR ² , where R ² is as defined above and X is a leaving group (e.g., a halide, a sulfuric acid ester, a sulfonic acid ester, a carboxylic acid ester, a triflate, an azide, an ammonium cation, etc.), in the presence of an anhydrous base (e.g., one or more alkali or alkaline earth metal salts of an alkoxide, hydroxide, carbonate, bicarbonate, hydride, amide, di syl or bis(trialkylsilyl)amide anion; an amine such as a trialkylamine, dimethylaminopyridine (DMAP) , diazabicyclo- nonane (DBN), diazabicycloundecane (DBU), etc.), and isolating the porphycene ether compound.

The reaction may be conducted in one or more organic aprotic or donor solvents (e.g., a dialkyl ether such as diethyl ether or methyl t-butyl ether, a cyclic ether such as tetrahydrofuran or dioxane, an aliphatic ester such as methyl acetate or ethyl acetate, a halogenated solvent such as dichloromethane or chloroform, an aromatic solvent such as toluene or benzene, amides such as dimethylfor amide or hexamethylphosphoroustriamide (HMPT) , dimethylsulfoxide, etc.) .

Generally, at least an equimolar amount of anhydrous base is combined with the starting tetrasubstituted hydroxy porphycene in a solvent, and the mixture is stirred at a temperature ranging from -78°C to 200°C. The tetrasubstituted hydroxyporphycene precursor (IV) is stirred in the presence of the anhydrous base and R ² X for a period of time sufficient to at least partially complete the reaction. Alternatively, the hydroxyporphycene may be irreversibly deprotonated (e.g. with NaH or lithium diisopropylamide (LDA) ) before the organic compound XR ² is introduced into the reaction mixture.

The porphycene ether product may be isolated and purified by extraction, chromatography, recrystallization, precipitation, etc., in accordance with known procedures.

The hydroxyporphycenes of formula (IV) may be prepared by the acid or base catalyzed hydrolysis of the acyloxy compounds (V)

where R ⁹ is alkyl, aralkyl or aryl.

The C-9 ether linkage is fairly stable under various chemical reaction conditions. Thus, if desired, chemical transformations of the terminal functionalities can take place. For example, terminal esters and amides can be

selectively hydrolyzed to the corresponding carboxylic acid using conventional hydrolysis conditions.

Metal complexes containing divalent metals, preferably complexes of smaller metals such as zinc, nickel, magnesium, tin, etc., and the porphycene compounds of the present invention can be easily prepared by the addition of metal salts (e.g. , metal acetates) to the porphycene compounds in an acid medium, such as glacial acetic acid. Demetallation occurs when the metal complex is reacted with concentrated sulfuric acid at room temperature with stirring. Hydrogen ions displace the metal atom during the demetallation reaction (Buchler, J. . in Smith, K. M. (Ed) : "Porphyrin and Metalloporphyrin", Elsevier, Amsterdam, 1975; Buchler, I. . in Dolphin, D. (Ed), "The Porphyrin", Vol. I, Academic Press, New York, 1978; Dorough et al., J. Am. Chem. Soc, 1951, 73:4315) .

The invention also includes pharmaceutically acceptable acid and base addition salts of the porphycene compounds which may be prepared by the known addition of acids such as HC1, HBr, H ₂ SO„, H ₃ P0 ₄ , malic acid, tartaric acid, maleic acid, fumaric acid, etc. Base addition salts are prepared by the addition of alkali and/or alkaline earth metal salts such as sodium, potassium, calcium and/or magnesium carbonates, bicarbonates, sulfates, phosphates, hydroxides, etc. as well as by addition of ammonia, amines (preferably primary, secondary and tertiary C _1-6 alkyl amines) , amino acids, etc. Any conventional acid or base addition salt which is

pharmaceutically acceptable is considered to be within the scope of the present invention.

The porphycene compounds of the present invention may be formulated as therapeutic formulations for administration to patients in need of photodynamic therapy for the treatment of cancer and/or dermatological conditions.

THERAPEUTIC FOPJΪULATIONS Therapeutic compositions containing the compounds of the present invention include liposome or microvesicle preparations, dispersions, solutions for systemic administration by intramuscular, intravenous or intraarterial bolus injection or infusion, etc. and topical dermatological preparations. In non-liposomal formulations, absorption of porphycenes within cells may be enhanced by inclusion of a cyclodextrin (e.g., one or more -, β- or γ-cyclodextrins, preferably a 0-cyclodextrin) .

Low frequency ultrasound (10-50 KHz) , combination of the dye with enhancers and/or use of occlusion techniques can assist in ensuring adequate drug delivery across the dermal barrier.

Parenteral Solutions

The photoactivatable porphycene dyes generally are used with additional solvents and adjuvants to prepare solutions suitable for intravenous injection. A number of solvents and co-solvents that are miscible with water and suitable surfactants can be used to achieve solutions for parenteral

use. The most important solvents in this group are ethanol, polyethylene glycols of the liquid series and propylene glycol. A more comprehensive listing includes acetone, N,N- dimethyl acetamide, N,N-dimethyl formamide, dimethyl sulfoxide ethanol, glycerin, polyethylene glycol 300, polyethylene glycol 400, propylene glycol, sorbitol, polyoxyethylene sorbitan fatty acid esters such as laureate, pal itate, stearate, and oleate, polyoxyethylated vegetable oil, sorbitan monopalmitate, 2-pyrrolidone, N-methyl-2-pyrrolidine, N-ethyl-1-pyrrolidine, tetrahydrofurfuryl alcohol, TWEEN 80 and dimethyl isosorbide. Dimethyl isosorbide (ARLASOLVE ^® DMI, ICI Specialty Chemicals) has the advantage of being both water- and oil-soluble. Additionally, dimethyl isosorbide may be readily gelled with a gelling agent to produce gel formulations with, for example, 4% KLUCEL ^® (Hercules) .

Other additives may be necessary to enhance or maintain chemical stability and physiological suitability. Examples are antioxidants, chelating agents, inert gases, buffers and isotonicifiers. Examples of antioxidants and typical concentration ranges include acetone sodium bisulfite (0.1-0.8%), ascorbic acid (0.05-1.0%), monothioglycerol (0.1-1.0%), potassium metabisulfite (0.05-0.1%), propyl gallate (0.02%), sodium bisulfite (0.01-1.0%), sodium formaldehyde sulfoxylate (0.03-0.1%), sodium metabisulfite (0.02-0.25%), sodium sulfite (0.01-0.1%) and sodium thioglycolate (0.05-0.1%).

Examples of chelating/complexing agents and typical concentration ranges include edetate sodium (0.005-0.1%),

edetate calcium disodium (0.005%-0.01%) , edetate trisodiu (e.g., 0.005-0.1%), gentisic acid ethanolamide (1.0%-2.0%), niacinamide (1.0%-2.5%), sodium citrate (0.01%-2.5%) , citric acid (0.001%-1.0%) , pentetic acid (e.g., 0.005-0.1%), deferoxamine (e.g., 0.005-0.1%), ditiocarb sodium (e.g., 0.005-0.1%) and succimer (e.g., 0.005-0.1%).

Examples of inert gases are nitrogen, argon and carbon dioxide.

Buffers are used primarily to stabilize a solution against the chemical degradation that might occur if the pH changed appreciably. Buffer systems employed normally have as low a buffer capacity as feasible in order to not disturb significantly the body buffer systems when injected. The buffer range and effect of the buffer on activity must be evaluated. Appropriate adjustment is useful to provide the optimum conditions for pH dependent partition into the target malignant tissues or lesion area.

Examples of such buffer systems include the following acids: acetic, adipic, ascorbic, benzoic, boric, hydrocyanic, citric, glycine, oxalic, lactic, malic, tartaric, hydrochloric, phosphoric, sulfuric, sulfurous, carbonic and bicarbonic; and their corresponding salts such as: potassium, sodium, magnesium, calcium and diethanolamine salts.

Osmoticity is of great importance and hypotonic solutions usually have their tonicity adjusted by the addition of salts such as sodium chloride, potassium chloride, magnesium chloride and calcium chloride and sugars such as dextrose, lactose, mannitol and sorbitol.

When the solution will be dispensed from multiple dose containers, antimicrobial agents in bacteriostatic or fungistatic concentrations must be added. Among the compounds and concentrations most frequently employed are phenylmercuric acid (0.002-0.01%), thimerosal (0.01%), benzethonium chloride (0.01%), benzalkonium chloride (0.01%), phenol or cresol (0.5%), chlorbutanol (0.5%), benzyl alcohol (2.0%), methyl p-hydroxybenzoate (0.18%), and propyl p-hydroxybenzoate (0.02%) . After the solution of the porphycene and optional additives has been compounded, the solution is generally filtered to remove particulate matter above 24 μm in size. A further step eliminating particulate matter down to 0.2 μm can eliminate microorganisms and accomplish cold sterilization. The solution is filled under aseptic conditions. The final solution can be additionally sterilized in its final container by thermal methods such as autoclaving or non-thermal methods such as ionizing radiation. The process of freeze drying (lyophilization) can be employed to avoid adverse thermal and oxidative decomposition and provide enhanced stability and improved solubility.

Topical Formulations

The porphycene compounds of the present invention may be formulated for topical application in penetrating solvents or in the form of a lotion, cream, ointment or gel containing a sufficient amount of the porphycene compound to be effective for PDT therapy of dermatological conditions.

Suitable penetrating solvents are solvents for the porphycene compound which will enhance percutaneous penetration of the porphycene compound. Solvents which have this property include dimethyl sulfoxide, dimethyl acetamide, dimethylformamide, l-methyl-2-pyrrolidone, diisopropyladipate, diethyltolua ide and to a lesser extent propylene glycol. Additional solvents include substituted azacycloalkan-2-ones having from 5 to 7 carbons in the cycloalkyl group such as l-dodecylazacycloheptan-2-one (AZONE) and other azacycloalkan-2-ones such as those described in U.S. 3,989,816, incorporated herein by reference.

Also included are N-bis-azocyclopentan-2-onyl alkanes described in U.S. 3,989,815 (incorporated herein by reference) , 1-substituted azacyclopentan-2-ones described in U.S. 3,991,203 (incorporated herein by reference) and water-soluble tertiary amine oxides described in U.S. 4,411,893 (incorporated herein by reference).

The topical formulations contain a sufficient amount of the porphycene compound to be effective in PDT therapy. Generally, concentrations in the range of 0.001 to 5 wt.%, preferably from about 1 to 5 wt.%, may be used. Typical lotion and cream formulations are shown below.

Additional topical formulations which may be used in conjunction with the porphycene compounds of the present invention are disclosed in U.S. 3,592,930 and U.S. 4,017,615 (incorporated herein by reference) .

Topical formulations may be prepared in gel form by combining the porphycene with a solvent such as alcohol,

dimethyl sulfoxide, propylene carbonate, diethyltoluamide (DEET) , diisopropyl adipate (DIPA) , etc. and adding a gelling agent. A preferred gelling agent is fumed silica (CAB-O-SILO ^® , Cabot Corp., Tuscola, IL) , and particularly grade M-5. The gelling agent is generally used in amounts of about 5-12 wt.% to obtain a gel with the desired viscosity. Obviously, gels containing more or less gelling agent will have slightly higher or lower viscosity. One skilled in the art can readily obtain the desired gel viscosity by adjusting the concentration of gelling agent. Additives, such as cosolvents and/or surfactants, frequently improve the gel properties and may be added as desired. Suitable cosolvents/surfactants include propylene glycol and glycerine. The additives may be incorporated into the gel by mechanically mixing the additives into a mixture of solvent and gelling agent.

Liposome or Microvesicle Preparations

Liposomes and methods of preparing liposomes are known and are described for example in U.S. 4,452,747 and U.S. 4,448,765, both of which are incorporated herein by reference. Liposomes are microvesicles which encapsulate a liquid within lipid or polymeric membranes. The porphycene compounds of the present invention may be incorporated into liposome microvesicles and used in this form for both topical and parenteral application. Topical and parenteral liposome preparations are known in the art. Sonified unila ellar

liposomes made from certain unsaturated lipids are known stable carriers for some of the porphycenes of the invention.

U.S. 4,837,028 discloses injectable liposome formulations having enhanced circulation time. The liposomes have a size of about 0.08-0.5 microns, contain at least 50 mole % of a membrane rigidifying component such as sphingomyelin and further contain about 5-15 mole % of ganglioside G _M1 . Liposome preparations for encapsulating sparingly soluble pharmaceutical compounds are disclosed in U.S. 4,721,612. The specifications of these U.S. patents are incorporated herein by reference.

After administration of a therapeutically effective amount of one or more of the porphycene compounds in the pharmaceutical composition or preparation, to a patient having a treatable condition such as a solid tumor (cancer) or psoriasis, for example, the patients affected body area is exposed to a therapeutically sufficient amount of light having an appropriate wavelength for absorption by the particular porphycene compound used. Suitable wavelengths of light for irradiating affected tissues are generally from about 600 to about 900 n , preferably from about 600 to about 700 nm, and more preferably at about 640 nm, or 680 nm if deeper tissue penetration is desirable. Irradiation of the accumulated porphycene usually generates singlet oxygen which is thought to be the actual lethal species responsible for destruction of the neoplastic cells, and hyperproliferative cells in general.

Photodynamic therapy using the porphycene compounds of the present invention has a number of advantages. The

porphycene compound itself is minimally toxic in the unexcited state. Each porphycene molecule can be repeatedly photoactivated and leads 30-60% of each time to cell-lethal events; that is, the generation of singlet molecular oxygen. The half-life of singlet molecular oxygen is approximately four microseconds in water at room temperature. The target cell is therefore affected, with minor opportunity for migration of the lethal singlet molecular oxygen to neighboring healthy tissue cells. Preferably, the singlet oxygen molecules rupture chemical bonds in the target cell wall or mitochondria resulting in destruction of the target cell. Destruction of target cell tissue commences promptly upon irradiation of the porphycene compounds. Indirect target cell death can also result from destruction of the tumor vascular system with concomitant restriction of oxygen supply. Photodynamic therapy using the compounds of the present invention is therefore selective and minimally toxic to healthy tissue. Singlet oxygen molecules produced which do not react rapidly decay to harmless ground state oxygen molecules.

Photodynamic therapy using the porphycene compounds of the present invention has the advantage that these compounds are more stable than their C-9 hydroxyporphycene analogs. In addition, the porphycene compounds of the present invention have the extra advantage that these compounds are capable of absorbing wavelengths of light of ca. 680 nm and thus are suitable for practical use with commercially available diode lasers. Furthermore, the present invention is appropriate for

PDT of deeper-seated tissues where light penetration of from up to about 0.6 cm to about 1.2 cm is desirable. This significantly longer-wavelength absorption is a direct consequence of the ether function being substituted directly onto the porphycene acrocycle itself. Ether functions on the R groups of formula (II), as in the tetrakis(alkoxyalkyl) - porphycenes, cause no significant shift of the longest wavelength absorption maximum.

A variety of phototherapy and irradiation methodologies are known to those skilled in the art and can be used with the novel porphycene compounds of the present invention. The time and duration of therapy and repetition of the irradiation treatment can be selected by the therapist (physician or radiologist) according to known photodynamic therapy criteria. The dosage of the porphycene compound may be varied according to the size and location of the target tissues which are to be destroyed and the method of administration. Generally, the dosage will be in the range of 0.05-10 mg of porphycene compound per kilogram of body weight, more preferably in the range of 0.1-5.0 mg/kg.

Irradiation generally takes place not less than one minute nor more than four days after parenteral administration of the porphycene compound. Usually, phototherapy is begun approximately from about 2 minutes to about 24 hours after systemic administration for either the tetrakis(alkoxyalkyl) - or the tetraalkylporphycenes. With topically administered dye, radiation may commence as soon as 30 seconds after dye application for treatment of psoriasis, genital warts,

bacterial infections, etc., but radiation up to 24 hours after due administration may be preferred, depending upon individual dye incorporation properties. Exposure to non-therapeutic light sources should be avoided immediately following phototherapy to minimize phototoxicity. Appropriate draping of the patient can be used to limit exposure of the area affected by phototherapy.

Light sources which are appropriate for use are well known in the art and may vary from non-coherent light sources with appropriate filters to lasers. As noted above, preferred wavelengths are from 600 to 900 nm, preferably from about 600 to about 700 nm, more preferably at about 640 nm, or 680 nm if deeper tissue penetration is desirable. The total amount of light which is applied to the affected area will vary with the method used and the location of the tumor or topical lesion or other hyperproliferative tissue characteristic of the condition to be treated. Generally, the amount of light is in the range of about 10 to 300 J/cm ² , preferably in the range of 20 to 250 J/cm ² , more preferably from 40 to 200 J/cm ² . Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified. Procedures which are constructively reduced to practice herein are described in the present tense and procedures which have been carried out in the laboratory are set forth in the past tense.

EXAMPLES

Example 1 - 9-ι'N-Boc-4-aminobutyroxy) -2.7.12.17-tetrakis- (methoxyethyl) orphycene (PbO _; method)

A solution of 108 mg (0.2 mmol) 2,7, 12, 17-tetrakis- (methoxyethyl)porphycene (TMPn) and 0.5 g N-Boc-4-aminobutyric acid in 20 mL dichloromethane was combined with 134 mg (0.6 mmol) Pb0 ₂ and stirred for 8-10 weeks at room temperature. The mixture was then poured into 100 L water and extracted with

50 mL dichloromethane. After washing the organic phase twice with 50 L of 5% aqueous sodium hydrogen carbonate and twice with water, the solvent of the separated organic layer was evaporated under vacuum. The residue was chromatographed with dichloromethane/ethyl acetate (1:1) on silica gel (column 15 x 4 cm) . The first eluted fraction contained starting material, 2,7, 12, 17-tetrakis(methoxyethyl)porphycene. Recrystallization of recovered starting material from dichloromethane/methanol afforded 27 mg. The next large fraction contained the desired product. Evaporation of the solvent and recrystallization of the residue from dichloromethane/n-hexane afforded the title compound in the form of small, blue needles having a melting point of 133-134°C. Yield: 47 mg, 31% (based on recovered TMPn: 42%). C ₄₁ H ₅₃ N ₅ 0 ₈ (743.8934 g/mole)

Mass Spectrum (FAB, NBA) : m/z 743(M*-, 38%), 688 ( [M+H--C ₄ H ₈ ]\ 10%), 558([M+H--BocNH(CH ₂ ) ₃ CO-] ⁺ - , 100%) , 527([M+H--BocNH(CH ₂ ) ₃ CO--CH ₃ 0-r, 19%) , 513([M+H--BocNH(CH ₂ ) ₃ CO--CH ₃ OCH ₂ -r, 18%) ,

481([M+H.-BθCNH(CH ₂ ) ₃ CO._ _CH3θCH2 .. _CH3θ . _{] 12%) f}

467 ( [M+H--BocNH(CH ₂ ) ₃ C0- -2CH ₃ OCH ₂ ^• ] ^** , 8%) ,

423 ([M+H--BocNH(CH ₂ ) ₃ CO--3CH ₃ OCH ₂ -) 8%) , 391([M-BocNH(CH ₂ ) ₃ CO--3CH ₃ OCH ₂ --CH ₃ 0- ] ^* , 7%) .

UV/VIS spectrum (CH ₂ C1 ₂ ) λ(ε) nmfmol^cm ^"1 ) :

370(144,700), 383(96,000) , 562(30,300), 605(33,700), 633(33,500), 639(32,300) .

IR spectrum (Csl) : v (cm ^"1 ) = 3364; 2979; 2927; 2872; 1749; 1708; 1686; 1528; 1458; 1367; 1251; 1221; 1118; 1171; 1000; 968; 893; 813; 628.

Example 2 - 9-Hvdroxy-2 ,7, 12.17-tetrakis- (methoxyethyl) orphycene

The synthesis of 9-acetoxy-2,7,12, 17-tetrakis-

(methoxyethyl) - porphycene is described in U.S. 5,179,120 (incorporated herein by reference). 240 mg (0.4 mmol) of 9-acetoxy-2,7, 12, 17-tetrakis(methoxyethyl)porphycene were dissolved in 150 mL of dry tetrahydrofuran and 15 L of absolute methanol. While stirring at room temperature, 162 mg (3 mmol) of sodium methoxide were added at once. The blue-green mixture was vigorously stirred for one minute, then diluted with 150 mL diethyl ether. The diluted mixture was extracted once with ice-cold 5% aqueous sodium chloride, then twice with water. Following drying of the separated organic phase over anhydrous sodium sulfate and filtering, the solvent was evaporated under vacuum and the residue was recrystallized

from tetrahydrofuran /n-hexane. The title compound was obtained in the form of small, blue needles which melt at 204-206°C with decomposition. Yield: 205 mg (92%) .

C ₃₂ H ₃₈ N ₄ 0 ₅ ( 558 . 7284 g/mol)

Mass spectrum (El, 70 eV) : m/z 558 (M ⁺ ' , 70%), 532 ( [M+2H" -CO] ^* ' , 22%), 526([M-CH ₃ OH] ⁺ ' , 25%), 513 ( [M-CH ₃ OCH ₂ ' ]\ 20%), 481 ([M-CH ₃ OCH ₂ '-CH ₃ OH] ⁺ , 60%).

UV/VIS spectrum (THF) λ(ε) nm(l mol ^"1 cm ^"1 ) : 366(116,900) , 387(73,000), 560(31,100), 625sh(35 ,400) . 636(44,000), 680(22,800).

IR spectrum (Csl) : v (cm ¹ ) = 3259; 2925; 1560; 1460; 1420; 1376; 1186; 1112; 1016; 994; 964; 893; 816.

Solubility in selected solvents:

Good: THF, DMSO, DMF, EGEE (ethylenglycol monoethyl ether)

Moderate: ethyl acetate Poor: ethanol, methanol Insoluble: water, hexane

Storage and handling informations: Solid 9-hydroxy-2,7,12,17-tetrakis(methoxyethyl)porphycene and even more its solutions must be stored refrigerated protected from light. The solutions, especially in CHC1 ₃ and CH ₂ C1 ₂ undergo decomposition to polar products (not yet defined exactly) .

Example 3 -

9-Methoxy-2.7.12.17-tetrakis(methoxyethyl)porphycene A solution of 56 mg (0.1 mmol) 9-hydroxy-2,7,12,17-tetrakis- ( ethoxyethyl)porphycene in 50 mL tetrahydrofuran was combined with 20 mL of 10% aqueous sodium hydroxide and vigorously stirred for 5 minutes at room temperature. The mixture was treated with 5 mL dimethylsulfate and stirred for an additional two hours. After washing the mixture thrice with 100 L of 5% aqueous sodium chloride, the solvent of the separated organic layer was evaporated under vacuum. The blue residue was chromatographed with dichloromethane/ethyl acetate (1:1) on .silica gel (column 20 x 4 cm). Following evaporation of the solvent and recrystallization from CH ₂ Cl ₂ /n-hexane of the residue from the main fraction, the title compound was obtained in the form of small, blue needles having a melting point of 121-123°C. Yield: 36 mg (64%).

C ₃₃ H ₄₀ N ₄ O ₅ ( 572 . 7028 g/mol )

Mass spectrum (El, 70 eV) : m/z 572 (M ^* ' , 100%), 557 ( [M-CH ₃ ' ] ^* , 8%), 527([M-CH ₃ OCH ₂ " ] 50%).

UV/VIS spectrum (CH ₂ C1 ₂ ) λ(ε) nm(l mol cm ^"1 ): 369(120,300), 385sh(82,200) , 563(27,700), 580sh(15,400) , 630(49,200), 679(16,500) .

IR spectrum (Csl) : v (cm ^"1 ) = 2978; 2870; 2806; 1557; 1459; 1392; 1320; 1206; 1176; 1121; 1024; 983; 897; 819; 536.

Solubility in selected solvents: Good: ethyl acetate, CHC1 ₃ , CH ₂ C1 ₂ , DMF, THF, DMSO, DEET, EGEE (ethylenglycol monoethyl ether) Poor: ethanol, methanol Insoluble: water, hexanes

Storage and handling information:

9-Methoxy-2,7,12, 17-tetrakis (methoxyethyl)porphycene forms stable crystals. As a precaution, solutions of this porphycene may be refrigerated and protected from light.

Example 4 - 9-Hexyloxy-2 ,7,12.17-tetrakis- (methoxyethyl) porphycene

A solution of 56 mg (0.1 mmol) 9-hydroxy-2,7, 12, 17- tetrakis (methoxyethyl)porphycene in 20 mL dimethylformamide was combined with 3 L of 1-bromohexane and 100 μl DBU with stirring under an inert atmosphere. After heating the mixture for 3-4 hours at 75°C, the green mixture was cooled to room temperature and diluted with 100 mL dichloromethane. The mixture was washed thrice with 100 mL of 5% aqueous sulfuric acid, then with water and then again with aqueous sodium hydrogen carbonate. The solvent of the separated organic layer was evaporated under vacuum. The blue residue was chromatographed with dichloromethane/ethyl acetate (6:1) on silica gel (column 15 x 4 cm) . After evaporating the solvent from the main fraction and recrystallizing the residue from CH ₂ Cl ₂ /methanol, the title compound was obtained in the form of violet needles having a melting point of 76-77°C. Yield: 30 mg (46%) .

C ₃₈ H ₅₀ N ₄ O ₅ (642.8368 g/mol)

Mass spectrum (El, 70 eV) : m/z 642 (M*', 7%), 557([M-(CH ₂ ) ₅ CH ₃ ^" ] ⁺ , 1%), 279 ( [M+H- -(CH ₂ ) ₅ CH ₃ ' ] ^2t , 8%).

UV/VIS spectrum (CH ₂ C1 ₂ ) λ(ε) nm(l mol ^"1 cm ^'1 ): 370(126,200) , 386sh(86,600) , 564(28,200), 631(54,500) , 681(17,100).

IR spectrum (Csl) : v (cm ^"1 ) = 2925; 2867; 1653; 1559; 1460; 1388; 1183; 1118; 1000; 892; 816.

Solubility in selected solvents:

Good: CH ₂ C1 ₂ , THF, toluene, DEET, DIPA, ethyl acetate, DMSO, DMF

Poor: ethanol, methanol, n-hexane Insoluble: water

Storage and handling information:

9-Hexyloxy-2,7, 12, 17-tetrakis(methoxyethyl)porphycene forms stable crystals. As a precaution, solutions of this porphycene may be refrigerated and protected from light.

Example 5 - 9-Nonyloxy-2 ,7, 12.17- tetrakis (methoxyethyl)porphycene

A solution of 56 mg (0.1 mmol) 9-hydroxy-2,7, 12, 17- tetrakis (methoxyethyl)porphycene in 20 mL dimethylformamide was combined with 3 mL of 1-bromononane and 100 μl DBU, then stirred under an inert atmosphere. After heating the mixture for 3-4 hours at 75°C, the green mixture was cooled to room temperature and diluted with 100 mL dichloromethane. The mixture was washed thrice with 100 mL of 5% aqueous sulfuric acid, then with water and then with aqueous sodium hydrogen carbonate. The solvent from the separated organic layer was evaporated under vacuum. The blue residue was chromatographed with dichloromethane/ethyl acetate (6:1) on silica gel (column 15 x 4 cm) . After evaporating the solvent from the main fraction and recrystallizing the residue from CH ₂ Cl ₂ /methanol, the title compound was obtained in the form of violet needles having a melting point of 82-83°C. Yield: 37 mg (54%).

C ₄₁ H ₅₆ N ₄ O _s ( 684 . 9172 g/mol )

Mass spectrum (El, 70 eV) : m/z 684 (M ⁺ ', 9%), 557([M-CH ₃ (CH ₂ ) ₈ " ] ^* , 2%), 57 (CH ₃ 0CH=CH ^* ' , 100%).

UV/VIS spectrum (CH ₂ C1 ₂ ) λ(ε) nm(l mol ^"1 cm ^"1 ): 370(126,800), 386sh(86,500) , 564(28,200), 631(54,400), 681(17,000) .

IR spectrum (Csl) : v (cm ^"1 ) = 2924; 2866; 1653; 1559; 1460; 1387; 1320; 1183; 1120; 1020; 993; 892; 820; 726.

Solubility in selected solvents:

Good: CH ₂ C1 ₂ , THF, toluene, DEET, DIPA, ethyl acetate, DMSO, DMF

Poor: ethanol, methanol, n-hexane Insoluble: water

Storage and handling information:

9-Nonyloxy-2,7, 12, 17-tetrakis(methoxyethyl) orphycene forms stable crystals. As a precaution, solutions of this porphycene may be refrigerated and protected from light.

Example 6 - 9-Dodecyloxy-2 ,7,12.17-tetrakis (methoxyethyl) porphycene

A solution of 56 mg (0.1 mmol) 9-hydroxy-2, 7, 12, 17- tetrakis (methoxyethyl)porphycene in 20 mL tetrahydrofuran was combined with 5 mL of 5% aqueous potassium carbonate and vigorously stirred for 15 minutes at room temperature. The mixture was treated with 0.5 mL of 1-iodododecane and stirred for an additional two hours at 80-85°C, then cooled to room temperature and diluted with 70 L dichloromethane. After washing the mixture thrice with 100 mL of 5% aqueous sodium chloride, the solvent from the separated organic layer was evaporated under vacuum. The blue residue was chromatographed with dichloromethane/ethyl acetate (4:1) on silica gel (column 12 x 4 cm) . After evaporating the solvent from the main fraction and recrystallizing the residue from CH ₂ Cl ₂ /methanol, the title compound was obtained in the form of long violet needles having a melting point of 77-78°C. Yield: 26 mg (35%).

C ₄₄ H ₆₂ N ₄ 0 ₅ (726.9976 g/mol)

Mass spectrum (El, 70 eV) : m/z 726(M ^*' , 100%) , 681([M-CH ₃ OCH ₂ ^' ] ^* , 3%) , 557 ( [M-CH ₃ (CH ₂ ) ' ] ^* , 25%) .

UV/VIS spectrum (CH ₂ C1 ₂ ) λ(ε) nm(l mol ^"1 cm ^"1 ) : 370(131,600) , 386sh(90,100) , 564(29,300), 631(57,700) , 681(18,100) .

Solubility in selected solvents:

Good: CH ₂ C1 ₂ , THF, toluene, DEET, DIPA, ethyl acetate, DMSO,

DMF Moderate: eyelohexane Poor: ethanol, methanol, n-hexane Insoluble: water

Storage and handling information:

9-Dodecyloxy-2,7,12,17-tetrakis(methoxyethyl)porphycene forms stable crystals. As a precaution, solutions of this porphycene may be refrigerated and protected from light.

Example 7 - 9-(p-Benzyloxy carboxylic acid methylester) - 2.7, 12, 17-tetrakis (methoxyethyl)porphycene

A solution of 56 mg (0.1 mmol) 9-hydroxy-2,7, 12, 17- tetrakis (methoxyethyl)porphycene in 20 mL dimethylformamide was combined with 1 g of methyl p-(α-bromomethyl) -benzoate and stirred under an inert atmosphere with 100 μl DBU. After heating the mixture for 40-60 minutes at 70-80°C, the green mixture was cooled to room temperature and diluted with 50 mL dichloromethane. The mixture was washed thrice with 100 mL of 5% aqueous sulfuric acid, then with water and then with aqueous sodium hydrogen carbonate. The solvent from the separated organic layer was evaporated under vacuum. The blue residue was chromatographed with toluene/ethyl acetate (2:1) on silica gel (column 20 4 cm) . The first small fractions eluted contained byproducts. After changing the toluene/ethyl acetate ratio from 2:1 to 1:2, the title compound (BOMeTMPn) was eluted from the column. After evaporating the solvent from the main fraction and recrystallizing the residue from CH ₂ Cl ₂ /n-hexane, the title compound was obtained in the form of small, blue needles having a melting point of 126-127°C. Yield: 35 mg (50%) .

3

C ₄₁ H ₄₆ N ₄ 0 ₇ (706.837 g/mol)

Mass spectrum (El, 70 eV) : m/z 708 ( [M+2H' ]', 2%), 558([M+H---CH ₂ C ₆ H ₄ C0 ₂ CH ₃ r- , 10%) , 526 ( [M-' CH ₃ -'CH ₂ C ₅ H ₄ C0 ₂ CH ₃ ] ^♦ ' , 3%) .

UV/VIS spectrum (CH ₂ C1 ₂ ) λ(ε) nm(l mol ^"1 cm" ¹ ): 371(136,200), 384sh(92,000) , 563(29,300), 581(16,300), 629(52,300), 675(16,700) .

IR spectrum (Csl) : v (cm ^"1 ) = 2869; 1722; 1612; 1559; 1460; 1383; 1281; 1175; 1113; 1020; 967; 894; 810; 756.

Solubility in selected solvents: Good: THF, CHC1 ₃ , CH ₂ C1 ₂ , EGEE Poor: ethanol, methanol Insoluble: water, hexane

Storage and handling information: BOMeTMPn forms stable crystals. As a precaution, the new compound and its solutions may be stored refrigerated protected from light.

Example 8 - 9-(p-Benzyloxy carboxylic acid)-2,7 , 12.17- tetrakis(methoxyethyl)porphycene 70 mg (0.1 mmol) of 9- (p-benzyloxy carboxylic acid methylester) -2,7,12, 17-tetrakis(methoxyethyl)porphycene was dissolved in 20 L tetrahydrofuran and 20 mL methanol.

Thereafter, 10 mL of 4 N aqueous sodium hydroxide was added

dropwise over the course of 5 minutes while stirring at room temperature. The reaction mixture was stirred for an additional hour and then neutralized. The desired product was precipitated with the addition of ice-cold 18% hydrochloric acid. The suspension was stirred for an additional hour, the flaky precipitate was then filtered off, washed with water and dried. For further purification, the blue residue was redissolved and concentrated in tetrahydrofuran, then the desired product was recrystallized from the concentrated solution by the addition of n-hexane. Melting point: 198- 200°C.

C ₄₀ H ₄₄ N ₄ O ₇ (692.8102 g/mol)

UV/Vis (C,H ₂ C1 ₂ ) : λ 372 (ε 123,400), 385 (sh83,900) , 563 (26,600), 629 (47,400), 676 (14,900)

IR(CsI) : 2974, 2924, 2871, 1695, 1559, 1461, 1314, 1295, 1222, 1173, 1113, 1082, 1018, 996.

Solubility in selected solvents: Good: THF, DMF, DMSO Moderate: aqueous solutions (pH>7) Poor: CHC1 ₃ , CH ₂ C1 ₂ , ethanol, methanol Insoluble: aqueous solutions (pH<7) , hexane

Storage and handling informations: 9-(p-Benzyloxy carboxylic acid)- tetrakis (methoxyethyl)porphycene forms stable crystals. As a precaution, the compound and its solutions may be stored refrigerated protected from light.

Example 9 - 9-Methoxy-2.7 , 12 , 17-tetra(n-propyl) orphycene A solution of 27 mg (0.05 mmol) 9-hydroxy-2,7, 12, 17- tetra(n-propyl)porphycene in 20 mL ether was combined with 15 mL 10% aqueous sodium hydroxide. After 15 minutes, 4 mL of dimethylsulfate was added with vigorous stirring. The mixed- phase reaction mixture was stirred for two hours. Next, the organic phase was washed four times with 50 mL of warm water (to remove the excess dimethylsulfate) , then dried over sodium sulfate. The dark-blue solution was chromatographed with hexane/chloroform (2:1) on silica gel (column 50 x 2.5 cm) . The first fraction eluted contained a small amount of 2,7, 12, 17-tetra(n-propyl)porphycene. The second fraction eluted contained the title compound (MeOTPPn) , which was then recrystallized from hexane/dichloromethane (2:1). The purified title compound had a melting point of 197-199°C. Yield: 15 mg (60%) .

C ₃₃ H ₄₀ N ₄ O(508.7052 g/mol)

Mass spectrum (El, 70 eV) : m/z 508 (M ^{* '} , 100%), 493 ( [M-CH ₃ ' ] ^* , 7%) , 477([M-CH ₃ 0" ] ^* , 10%), 254(M ^2* , 13%), 225([M-2C ₂ H _S ' ] ^2t , 8%)

UV/VIS spectrum (CH ₂ C1 ₂ ) λ(ε) nm(l mol ¹ cm ^"1 ): 370(98,000), 386sh(67,000) , 562(21,000), 628(37,000), 677(11,000).

IR spectrum (Csl) : v (cm ¹ ) = 2958; 2928; 2868; 1561; 1460; 1376; 1204; 1170; 1030; 981; 895; 810.

Solubility in selected solvents: Good: ethyl acetate, CHC1 ₃ , CH ₂ C1 ₂ , DMF, THF Poor: DMSO

Insoluble: water, hexane

Storage and Handling Informations:

MeOTPPn forms stable crystals and solutions. As a precaution, its solutions may be stored in a refrigerator protected from light.

Example 10 - 9-Methoxyoxymethylen-2.7.12.17-tetra (n-propyl) orphycene A solution of 54 mg (0.1 mmol) 9-acetoxy-2,7,12,17- tetra(n-propyl)porphycene in 300 mL absolute ether was reacted with 50 mL of a 0.02 M solution of sodium methoxide in methanol at room temperature. After five minutes, 3 mL of chloromethyl methyl ether in methyl acetate (prepared from acetyl chloride and dimethoxymethane according to a known procedure) was added to the saponified acetoxyporphycene, and the mixture was stirred for two hours at room temperature. The reaction was washed thrice with 50 mL of water. The organic phase was dried over sodium sulfate, filtered, stripped of solvent and then placed in a drying pistol. The residue was chromatographed with diethyl ether/petroleum ether (2:5) on silica gel. The first fraction eluted contained the title compound. Recrystallization from hexane gave pure, densely grouped violet needles of the title compound having a melting point of 123°C. Yield: 21-30 mg (40-55%).

Mass spectrum ( El , 75 eV) : m/ z 539 ( [M+H T , 75% ) , 538 (M ^* \ 100% ) , 494 ( [M+H ^' -CH ₃ OCIV ] \ 70% ) , 493 ( [M-CH ₃ OCH ₂ - ] ^* , 95% ) ,

479([M-CH ₂ 0-CH ₃ CH ₂ ' ] ^* , 25%), 464 ( [M-CH ₃ OCH ₂ ' -CH ₃ CH ₂ " ] 25%), 437([M+H'-CH ₃ OCH ₂ '-CO-CH ₃ CH ₂ ' ] ^♦ , 15%), 407

([M+H--CH ₃ OCH ₂ ^' -3CH ₃ CH ₂ - ] ^* , 30%) , 378 ( [M+H ^' -CH ₃ OCH ₂ ' -4CH ₃ CH ₂ - ]*, 10%), 349([M-CH ₃ OCH ₂ ^' -4CH ₃ CH ₂ '-CO] ⁺ , 10%), 45 (CH ₃ OCH ₂ ⁺ ' , 25%) .

UV/VIS spectrum (Hexane) λ(ε) nm(l mol ^"1 cm ^"1 ): 246(14,200), 306sh(12,700) , 369(137,000), 382sh(89,000) , 530sh(5,000) , 561(32,500), 618(42,600), 631(37,400), 666(18,400).

IR spectrum (Csl) : v (cm ^"1 ) = 2958; 2827; 2868; 1150; 1052; 1560; 1460; 1376; 1311; 1217; 969; 900; 809; 746; 516.

Example 11 - 9- (p-Benzyloxy carboxylic acid methyl ester) -

2.7 , 12.17-tetra- (n-propyl)porphycene

A solution of 98 mg (0.2 mmol) 9-hydroxy- tetrapropylporphycene in 50 ml dimethylforamide was combined with 1 g of 4-(bromomethyl) -benzoic acid methylester, stirred under protective gas and treated with lOOμl DBU. After heating the mixture 40-60 minutes (DC-controlled, silica gel dichloromethane/hexane 2:1) at 75-80°C, the green solution was cooled to room temperature and treated with 50 ml dichloromethane. The mixture was washed thrice with 100 ml of 5% aqueous sulfuric acid, then with water and 5% aqueous sodium hydrogen carbonate. The separated organic layer was evaporated under vacuum, the blue residue chromatographed with dichloromethane/hexane (2:1) on silica gel (column 20x4 cm) . Evaporation of the solvent and crystallization of the residue of the main fraction from CH ₂ Cl ₂ /n-hexane, the title compound

was obtained in the form of small, blue needles having a melting point of 176-177°C. Yield 69 mg (54%) . C ₄₁ H ₄₆ N ₄ 0 ₃ (642.8394 g/mol)

Example 12 - 9-(p-Benzyloxy carboxylic acid)-2,7.12.17-tetra- n-propylporphycene

130 mg (0.2 mmol) 9-(p-Benzyloxy carboxylic acid methylester)-tetrapropylporphycene were dissolved in 100 ml tetrahydrofuran, combined with 40 ml methanol and 20 ml of 4N aqueous sodium hydroxide were added dropwise within 5 minutes while stirring a room temperature. The reaction was stirred for an additional hour, neutralized and then precipitated under acidic conditions with the addition of ice-cold 18% hydrochloric acid. The suspension was stirred for an additional hour, the flaky precipitate was filtered off, washed with water and dried. For further purification, the blue residue was redissolved in hot ethyl acetate, the main solvent evaporated and the concentrated product solution recrystallized after addition of n-hexane. The title compound was obtained in the form of small, blue crystals which decompose without melting above 300°C. Yield: 60 mg (48%) and mother liquors. C ₄₀ H ₄₄ N ₄ O ₃ (628.8126 g/mol)

UV/VIS spectrum (THF) λ nm(ε) : 371(131,700) , 562(28,800), 629(49,600) , 677(15,300) .

IR spectrum (Csl) : v = 2956; 2929; 2869; 1691; 1621; 1559; 1463; 1423; 1375; 1314; 1282; 1203; 1173; 1157; 1092; 1019; 981; 894; 851; 810; 752 cm ^"1 .

Solubility in selected solvents:

Good: THF, EGEE

Moderate: DMSO, DEET, DMF, ethyl acetate

Poor: ethanol, methanol, CHC1 ₃ , CH ₂ C1 ₂

Insoluble: water, hexane

Storage and handling information:

9-(p-Benzyloxy carboxylic acid) -2,7, 12, 17-tetra(n- propyl)porphycene forms stable crystals. As a precaution, solutions of this porphycene may be refrigerated and protected from light.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.