147-94-4

-

-

-

-

-

An anti-tumour agent of cytarabine (ara-C) was conjugated with a 2-oxopropyl group at the N(4) position to obtain a radiation-activated prodrug (oxo-ara-C) that targeted hypoxic tumour tissues with selective cytotoxicity. The parent anti-tumour agent, ara

-

5'-O-acyl and 5'-O-alkoxycarbonyl derivatives of α-, anhydro-, xylo- and arabinonucleosides could be obtained through a lipase-mediated reaction with SP 435 lipase (from Candida antarctica) by using acetoxime butyrate or butyric anhydride, together with benzyloxycarbonyl-O-acetoxine as acylating agents. Alkoxycarbonylation gave poorer yields than acylation and other lipases tested gave non-selective reaction or not reaction at all.

A method is described for the synthesis of purine D-arabinonucleosides that uses purine bases and 2,2'-anhydro-(1-β-D-arabinofuranosylcytosine), AraC-an, as the starting materials.AraC-an was chosen as the precursor to the D-arabinosyl donor, because it is more readily available than any of the products that may be sequentially derived from it, namely, 1-β-D-arabinofuranosylcytosine ( AraC ), 1-β-D-arabinofuranosyluracil ( AraU ), and α-D-arabinofuranosyl-1-phosphate ( Araf 1-P ), a D-arabinofuranosyl donor.Four reactions were involved in the ovarall procass; ( a ) AraC-an was nonenzymically hydrolyzed at alkaline pH to AraC which was then ( b ) deaminated by deaminase to AraU, a nucleoside, ( c ) phosphorylyzed by uridine phosphorylase to Araf 1-P, and ( d ) this ester caused to react with a purine base to afford a purine D-arabinonucleoside, the reaction being catalyzed by purine nucleoside phosphorylase.All four rections occured in situ, the first and second being performed sequentially, whereas the third and fourth were combined in a single step.The three enzyme catalysts were purified from Escherichia coli.The efficiency of the method is exemplified by the synthesis of the D-arabinonucleosides of 2,6-diaminopurine and adenine; the overall yields, based on AraC-an, were 60 and 80 percent respectively.

A biocatalytic process for producing active pharmaceutical ingredients (APIs) or intermediates thereof, wherein those APIs or their intermediates are nucleoside analogues (NAs) of formula I and wherein said NAs are active as pharmaceutically relevant antivirals and anticancer medicaments, intermediates or prodrugs thereof.

A series of new 5-halogeno-1-(β-L-arabinofuranosyl)uracils and their cytosine analogues were synthesized by halogenation of ara-L-uridine and ara-L-cytidine, respectively. The 5-(2-thienyl) and 5-halogenothienyl derivatives of both series were also prepared in excellent yields by Stille coupling followed by halogenation. All of these syntheses were based on benzoyl-protected derivatives. In vitro cytotoxicity experiments carried out using L1210 mouse leukemia cells showed that 5-(2-thienyl)- ara-L-uridine was the most potent compound of the new compounds; the majority of the analogues were not effective up to 200 μM concentrations. Copyright Taylor and Francis Group, LLC.

A novel pharmaceutical composition for treating or preventing hepatocellular carcinoma and a method of treatment are provided. A pharmaceutical composition for treating or preventing liver cancer is obtained by combining a chemotherapeutic agent with an anti-glypican 3 antibody. Also disclosed is a pharmaceutical composition for treating or preventing liver cancer which comprises as an active ingredient an anti-glypican 3 antibody for use in combination with a chemotherapeutic agent, or which comprises as an active ingredient a chemotherapeutic agent for use in combination with an anti-glypican 3 antibody. Using the chemotherapeutic agent and the anti-glypican 3 antibody in combination yields better therapeutic effects than using the chemotherapeutic agent alone, and mitigates side effects that arise from liver cancer treatment with the chemotherapeutic agent.

The gas-phase encounters between 2-aminobutane and proton-bound chiral resorcin[4]arene/nucleoside complexes behave in the gas phase as supramolecular "chiroselective logic gates" by releasing the nucleoside depending on the resorcin[4]arene and the 2-aminobutane configurations.

Monoclonal antibodies that bind specifically to Claudin 3 expressed on cell surface are provided. The antibodies of the present invention are useful for diagnosis of cancers that have enhanced expression of Claudin 3, such as ovarian cancer, prostate cancer, breast cancer, uterine cancer, liver cancer, lung cancer, pancreatic cancer, stomach cancer, bladder cancer, and colon cancer. The present invention provides monoclonal antibodies showing cytotoxic effects against cells of these cancers. Methods for inducing cell injury in Claudin 3-expressing cells and methods for suppressing proliferation of Claudin 3-expressing cells by contacting Claudin 3-expressing cells with a Claudin 3-binding antibody are disclosed. The present application also discloses methods for diagnosis or treatment of cancers.

(Chemical Equation Presented) Kinetics of the hydrolytic reactions of four bisphosphonate derivatives of nucleoside antimetabolites, viz., 5-fluorouridine 5′-β,γ-(1-hydroxyethylidene) triphosphate (4), 5-fluorouridine 5′-β,γ-methylene triphosphate (5), ara-cytidine 5′-β,γ-(1-hydroxyethylidene) triphosphate (6), and ara-cytidine 5′-β,γ-methylene triphosphate (7), have been studied over a wide pH range (pH 1.0-8.5) at 90°C. With each compound, the disappearance of the starting material was accompanied by formation of the corresponding nucleoside 5′-monophosphate, the reaction being up to 2 orders of magnitude faster with the β,γ-(1-hydroxyethylidene) derivatives (4, 6) than with their β,γ-methylene counterparts (5, 7). With compound 7, deamination of the cytosine base competed with the phosphate hydrolysis at pH 3-6. The measurements at 37°C (pH 7.4) in the absence and presence of divalent alkaline earth metal ions (Mg2+ and Ca2+) showed no sign of metal ion catalysis. Under these conditions, the initial product, nucleoside 5′-monophosphate, underwent rapid dephosphorylation to the corresponding nucleoside. Hydrolysis of the β,γ-methylene derivatives (5, 7) to the corresponding nucleoside 5′-monophosphates was markedly faster in mouse serum than in aqueous buffer (pH 7.4), the rate-acceleration being 5600- and 3150-fold with 5 and 7, respectively. In human serum, the accelerations were 800- and 450-fold compared to buffer. In striking contrast, the β,γ-(1-hydroxyethylidene) derivatives did not experience a similar decrease in hydrolytic stability. The stability in human serum was comparable to that in aqueous buffer (τ1/2 = 17 and 33 h with 4 and 6, respectively), and on going to mouse serum, a 2- to 4-fold acceleration was observed. To elucidate the mineral-binding properties of 4-7, their retention on a hydroxyapatite column was studied and compared to that of zoledronate (1a) and nucleoside mono-, di-, and triphosphates.

The present invention relates to a compound of formula (1), or a pharmaceutically acceptable salt thereof, Formula: (1); wherein: R1 is a substituted aryl or heteroaryl group bearing at least one nitro or azido group or is an optionally substituted benzoquinone, optionally substituted naphthoquinone or optionally substituted fused heterocycloquinone; R2 is H, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, aryl or heteroaryl; and R3 is selected such that R3NH2 represents a cytotoxic nucleoside analogue or an ester or phosphate ester prodrug of a cytotoxic nucleoside analogue, with the proviso that if R1 is an aryl group then R2 is not H.

Methods of stimulating an immune response and treating patients responsive thereto with 3,4-di(1H-indol-3-yl)-1H-pyrrole-2,5-diones, staurosporine analogs, derivatized pyridazines, chromen-4-ones, indolinones, quinazolines, nucleoside analogs, and other small molecules are disclosed.

Methods and preparations for treating disorders of the eye and/or causing dissolution of corneal proteoglycans and organized healing of corneal stroma, softening of the cornea for non-surgical refractive correction of eyesight, removing corneal haze and opacification, inhibiting fibroblasts and preventing corneal fibrosis and scar formation, treating pterigiums and treating corneal neovascularization as well as iris neovascularization. Preparations containing a) urea, b) urea derivatives (e.g., hydroxyurea, thiourea), c) antimetabolites, e) urea, urea derivatives, non-enzymatic proteins, nucleosides, nucleotides and their derivatives (e.g., adenine, adenosine, cytosine, cytadine, guanine, guanitadine, guanidinium, guanidinium chloride, guanidinium salts, thymidine, thymitadine, uradine, uracil, cysteine), reduced thioctic acid, uric acid, calcium acetyl salicylate, ammonium sulfate, isopropyl alcohol, ethanol, polyethylene glycol, polypropylene glycol or other compound capable of causing nonenzymatic dissolution of the corneal protoeglycans or f) any of the possible combinations thereof, are administered to the eye in therapeutically effective amounts.

The present invention relates to a compound of formula (1), or a pharmaceutically acceptable salt thereof, wherein: Ar is a substituted aryl or heteroaryl group bearing at least one nitro or azido group or is a group of formula (2) or (3) wherein R1, and R2, which may be the same or different are independently optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, aryl, COR3 or, together with the intervening carbon atom, form an optionally substituted heterocycloalkyl or carbocyclic ring ; L is -OC(O)- or -OP(O)(OR6)-; n is0or1;X is 0, S, NR7 or a single covalent bond; R3 is OR4 or NR4R5; R4, R5, R6 and R7 are each independently hydrogen or optionally substituted alkyl or, where Rr is NR4R5, R4 and R5 can be joined to form, together with the intervening nitrogen atom, a heterocycloalkyl ring; R8 is hydrogen, alkoxy or diatkylaminoalkyl; R9 is optionally substituted alkyl; Rio is hydrogen, alkyl, alkoxy or dialkylaminoalkyl; R11 and R12 are independently hydrogen, alkyl, alkoxy, thioatkoxy, amino, alkylamino, dialkylamino, morpholino, piperidino,piperazino or l=aziridinyl; A is an optionally substituted aryl or heteroaryl ring; and Dr is a moiety such that DrXH represents a cytotoxic or cytostatic compound.

Methods and preparations for treating disorders of the eye and/or causing posterior vitreous disconnection or disinsertion. Preparations containing a) urea, b) urea derivatives (e.g., hydroxyurea, thiourea), c) a non-steroidal anti-inflamatory agents, d) antmetabolites, e) urea, urea derivatives, non-enzymatic proteins, nucleosides, nucleotides and their derivatives (e.g., adenine, adenosine, cytosine, cytadine, guanine, guanitadine, guanidinium, thymidine, thimitadine, uradine, uracil, cystine), uric acid, calcium acetal salicylate, ammonium sulfate or other compound capable of causing non-enzymatic dissolution of the hyaloid membrane or e) any of the possible combinations thereof, are administered to the eye in therapeutically effective amounts.

As a part of azide prodrug approach, we synthesized a 4-azido analog of ara-C (4) as a prodrug for ara-C. The compound 4 was obtained from 1-(β-D-arabinofuranosyl)uracil (1) in three steps. At pH 7.0 and 11.0, a loss of UV absorption of the compound 4 was observed resulting from a transformation that was proved by identifying the transformed product 5 by 1-D, and 2-D NMR as well as tandem mass spectral studies. In NMR studies, changes in the chemical shifts were observed at positions 5, 6, 1′, and 2′ between the compounds 4 and 5. A molecular peak at m/z 270.1 (MH+) was observed in the mass spectra of compounds 4 and the transformed product 5. A fragment at 180.2 was identified to be the compound 6, containing the 6,2′-anhydro linkage of compound 5. The X-ray analysis indicated that compound 4 exists as l-(β-D-arabinofuranosyl)tetrazolo[4,5-c]pyrimidin-2-one, with the azide moiety cyclized. To understand if the chemical instability of the nucleoside 4 was due to the arabino configuration of 2′-OH or due to the azido moiety, we also studied 1-(2,3-dideoxy-2-fluoro-β-D-arabinofuranosyl)tetrazolo[4,5-c]p3Timidin-2- one (11) and 4-azido-1-methyl-2-pyrimidinone (15). At pH 2.0 and 7.0, similar UV profiles were observed for compounds 11 and 15. However, at pH 11.0, λmax shifted slowly to lower wavelength for both compounds 11 and 15. In a separate kinetic study, they were stable at pH 7.4 for up to 2.45 h. From the NMR and high-resolution mass spectral studies, it was concluded that in the presence of ammonium hydroxide, an addition of amine occurred at 6-position of compound 11. Thus, the stability profiles of compounds 4, 11, and 15 were different. The instability and the formation of 2′,6-anhydro bond in compound 4 in nonacidic media was due to the presence of 2′-OH in the arabino configuration and probably not due to the azide group.

A novel process is provided for producing a nucleoside, such as cytarabine, or a nucleoside analogue, comprising the step of reacting 2,2'-O-cyclonucleoside or an analogue thereof with an amine. Preferably, the process is conducted in the presence of an aqueous solvent. A novel process for the production of the precursor 2,2'-O-cyclonucleoside compounds and pharmaceutically acceptable salts thereof is also provided which comprises reacting a 2,3'-O-diaikylstannylene nucleoside compound with an amine in the presence of a sulfonyl compound. Cytarabine is a known antineoplastic and antiviral agent.

Two mutual prodrugs, in which two different anti-cancer drugs are attached to the same molecule via labile linkages, are synthesized and examined kinetically. One of the mutual prodrugs loses a drug component under physiological conditions within an hour, but the other mutual prodrug (having a longer spacer between the two drugs) is stable to chemical degradation even at hither pH values. Thus, enzymatic hydrolysis alone will release the two anti-cancer drugs. The potential value of anti-cancer mutual prodrugs is discussed.

N4-Dipeptidyl slow-release forms of the anticancer drug ara-C were prepared by acylation of the lithiated nucleotide with 4,4-dialkyloxazolinones. An azapeptide prodrug of ara-C was obtained by condensation of an amino acid hydrazide with an activated nucleotide urea. The use of unnatural amino acid residues at N4 prevented nonspecific proteolytic cleavage in biological medium. Ara-C prodrugs 10, 15, 17, and 19 released active drug with half-lives from a few minutes to several days, respectively. Activation via intramolecular N4-deacylation did not require enzymatic intervention but was strictly dependent on the structure of the peptide chain. The prodrugs 10, 15, and 17 produced similar growth inhibition as ara-C in cultured murine leukemia cells while the azapeptide prodrug 19 was less potent reflecting the slow release of active drug with this compound. All four prodrugs retained the ability to induce apoptosis in human HL-60 leukemia cells with kinetics dictated by the rate of intramolecular N4-deacylation. This is the first demonstration for the control of apoptotic cell death by the modulation of drug release from prodrugs.

The enzymatic hydrolysis of a series of Cytarabine-N4-carboxylate (3a-h) and succinamate (4a-f) ester prodrugs by porcine liver esterase (PLE) has been investigated. It was shown that variation of steric parameters such as van der Waal's volume of the ester side chain (V(XR')), molecular bulkiness (V(m)) and linear dimensions (L) can clearly influence the rate of conversion of the prodrugs to the parent Ara-C. Regression analysis of the results permitted the prediction of minimum (V(XR')) values of 51.5 A3 and 85.0 A3 for the carbamates and succinamates, respectively. In general, the carbamate esters 3a-h were more resistant to hydrolysis by PLE than the succinamates 4a-f. The rate of hydrolysis increased as the molecular bulkiness (V(m)) increased, but this effect can be compensated in some cases by the inverse correlation of the linear dimension (L) as in case of the cholesteryl ester prodrug. The study indicates that, through a suitable choice of an ester group with balanced V(m) and L parameters, one can tune up the enzymatic hydrolysis of Ara-C prodrugs by PLE.

A general and convenient method for the synthesis of several pyrimidine and purine nucleosides by selective oxidation of thionucleosides with dimethyldioxirane is reported. Thioketo moieties in the C-4 position of the pyrimidine ring, and in the C-6, and C-8 positions of the purine ring are the domain of oxidative nucleophilic substitution. Thioketo moieties in the C-2 position of both purine and pyrimidine rings are the domain of desulfurization or formation of disulfides.

1-β-L-Arabinofuranosylcytosine (β-L-Ara-C, 7) and 2'-deoxy-2'-methylene- β-L-cytidine (β-L-DMDC, 14) have been synthesized via a multi-step synthesis from L-arabinose. These compounds were tested in vitro against L1210, P388, Sarcoma 180, and CEM cells, and found not to be active at a concentration up to 100 μM. β-L-Ara-C and β-L-DMDC were also tested against HSV-1 and HSV-2 and yielded ID50 values of >100 μM.

Amino acid and hydroxyamino acid transporter compounds are provided, in which an amino acid or hydroxyamino acid as a carrier is linked via an ester linkage to a therapeutic compound, and having one of the general formulae: in which AA represents the amino acid or hydroxyamino acid, HAA represents the hydroxyamino acid, and Z1 and Z2 represent a therapeutic compound, or a linking compound attached to COOH or OH of the hydroxyamino acid and to the therapeutic compound, as well as a process for preparing the same, and a process for administration of the same to animals, to obtain the benefit of the therapeutic effect of the therapeutic compound.

The kinetics of conversion of the prodrug ancitabine to the anti-cancer drug cytarabine have been studied in aqueous solutions in the pH range of 1.5-10.7, temperature range of 19.5-80.0°C, ionic strength range of 10-4 to 1.5, and in the presence of several general-base catalysts. Under all conditions ancitabine was quantitatively converted to cytarabine. The pH-rate profiles were linear with slope = 1 in alkaline pH, becoming pH independent in the region of maximum stability at pH ≤4, where buffer catalysis was found to be insignificant and k(obs) ? (1.12 x 1011 h-1)·exp {-10121 deg/T}. At 30°C, pH ≤4, it is calculated that an aqueous ancitabine solution will maintain 90% of its initial concentration for 12 d. A novel method for measuring general-base catalysis in competition with predominating a specific-base catalysis and in the presence of secondary salt effects a constant ionic strength was developed. Three mechanisms of hydrolytic prodrug conversion are proposed: nucleophilic hydroxide addition, general base-assisted nucleophilic water attack, and spontaneous water attack.

New synthetic methods of 1-(β-D-arabinofuranosyl)-pyrimidines are described. 1-(β-D-arabinofuranosyl)-uracil, 1-(β-D-arabinofuranosyl)-5-fluorouracil, 1-(β-D-arabinofuranosyl)-thymine, and 1-(β-D-arabinofuranosyl)-cytosine can be obtained in a high yield by the splitting of the anhydrobond in 2,2'-anhydropyrimidines in dipolar aprotic solvents, such as HMPT, DMF, and DMSO, respectively, in the presence of activated elemental copper.Unlike the formation of cyclopyrimidines ribonucleosides are directly transformed to the corresponding arabinofuranosyl derivatives by the reaction with diphenylcarbonate and NaHCO3 in the presence of copper.The reaction proceeds probably via an intermediate formation of the cycloproduct.Further aspects on the mechanism are described.

Treatment of the acetylated derivative (3b), which was prepared from uridine in 86 percent overall yield, with tri(1H-1,2,4-triazol-1-yl)phosphine oxide gave compound (6a) in high yield, and with 3-nitro-1,2,4-triazole and diphenyl phosphorochloridate it gave compound (6b) in high yield.When the former product (6a) was allowed to react with ammonia, methylamine, dimethylamine, and morpholine at room temperature, and the products further deacetylated if necessary, ara-C (1; R1=R2=H) and its corresponding 4-N-alkyl derivatives (1; R1=H, R2=Me), (1: R1=R2=Me), and 1,R2= -(CH2)2O(CH2)2-> were obtained in very high yields. 4-N-Phenyl-ara-C (1; R1=H, R2=Ph) was obtained in high yield when compound (6a) or (6b) was heated with aniline in pyridine solution and the products then deacetylated.The nitro-compound (6b) was converted into the ara-C derivative (1; R1=H, R2=CH2CO2Me), and the sulphide (7) was obtained following the deacetylation of the products of the reaction between the 1,2,4-triazolyl derivative (6a), toluene-p-thiol, and triethylamine.

First-order rate constants (k(L)) for hydrolysis of p-nitrophenyl acetate, cationic cyclocytidine, and anionic indomethacin in the presence of buffered liposomal suspensions of positive, negative, and neutral charge were compared to those determined in the corresponding buffers (k(B)) using the ratio, R(k) = k(L)/k(B). Association between the reactants and the liposomes was evaluated by comparing assays for concentration in the filtrates (C(F)) with the total concentration in the liposomal suspension (C(T)) using R(C) = C(F)/C(T). Liposomes did not influence cyclocytidine hydrolysis rates and no association was observed (R(k) ? R(C) ? 1). In contrast, indomethacin showed ~80% reduction in hydrolysis rate and ~80% liposome association value (R(k) ? 0.2 ? R(C)). In neutral and negatively charged liposomal suspensions, p-nitrophenyl acetate displayed ~30% decrease in k(B) (R(k) ? 0.7) together with ~90% liposomal association (R(C) ? 0.1). However, hydrolysis was greatly accelerated in positively charged liposomal suspensions. Loss was described by a biexponential equation where α is the fast and β is the slow pre-exponential coefficient and α/β/k(B) = 39:6:1. The observed relationships between hydrolysis rates and reactant-liposome associations are reconciled in terms of the hydrophilicity of the reactants and the potential influence of the liposomes on the expected transition states for the hydrolysis reactions.

The conformations of the sugar moieties of a number of α-D- and -L-arabinofuranosyl nucleosides in solution have been investigated, largely with the aid of a statistical procedure developed for this purpose.The overall results demonstrated the existence, for a broad range of analogs, of a two-state, conformational equilibrium, NS (or 2E3E).As between different analogs, there is a large variation in the relative populations of these two states that is related to the nature of the aglycon, the type of protecting groups on the sugar hydroxyl groups, and, to a much smaller extent, the solvent system.There is a striking correlation between the conformation of the sugar and the orientation of the exocyclic, hydroxymethyl group.Both for purine and pyrimidine nucleosides, a preponderance of the gauche-gauche rotamer of the exocyclic group is associated with the type-N state of the furanose ring, whereas, with the type-S state, the gauche-gauche rotamer population is virtually nonexistent.A comparison with X-ray diffraction data for 9-α-D-arabinofuranosyladenine demonstrated that, as for other classes of nucleosides, the solid-state conformation corresponds to one of the states participating in the equilibrium in solution.

Syntheses of five pairs of cytosine and 5-fluorocytosine xylofuranosyl nucleosides in which the 3'-hydroxyl group is replaced by Cl, Br, I, OMs, or OTs are described.Those xylosyl nucleosides with a good leaving group at the 3' position exhibit good inhibitory activity against L5178Y and P815 mouse leukemic cells in vitro at rather low concentrations, and like that of ara-C this cytotoxicity is reversed by 2'-deoxycytidine but not by thymidine.Xylosylcytosines are not active against ara-C resistant lines of L5178Y and P815 cells; however the corresponding 5-fluorocytosine analogues exhibit significant cytotoxicity against these ara-C resistant leukemic cell lines, and this activity is reversed by thymidine but not by deoxycytidine.These data support the "double-barreled" masked precursor hypothesis in that xylosyl-5-fluorocytosines substituted at the 3' position by a good leaving group exhibit activity akin to that of ara-C in the ara-C in the ara-C sensitive lines, while these nucleosides act as 5-fluoropyrimidines in the ara-C resistant lines.

-

A new method for preparing cytosine arabinoside involving the cyanovinylation of the aminooxazoline of D-arabinose by cis-β-[trimethylammonium]-acrylonitrile tosylate. Also included are new preparations of the aminooxazoline of D-arabinose and the anion of cis-1-cyano-2-hydroxyethylene. DESCRIPTION OF THE PRIOR ART Cytosine arabinoside, an anti-leukemic agent also known as 1-β-D-arabinofuranosylcytosine, is a known anti-leukemic agent. Consequently, an economical and safe synthesis of the compound and other significant cytosine nucleosides is an important contribution to the well being of the populace. The Orgel and Sanchez patent, U.S. Pat. No. 3,658,788, provided a new way of preparing cytosine nucleosides, particularly cytosine arabinoside. The process consisted of preparing an aminooxazoline intermediate which is then cyanovinylated to a cyclocytidine salt. The cyclocytidine salt is then treated with aqueous ammonia to form the cytosine nucleoside. However, difficulties accompany these synthetic pathways. In the cyanovinylation step, many of the electrophilic reagents were too costly to use in a commercially oriented process. Those reagents that were commercially feasible, cost-wise, suffered from other serious defects. Cyanoacetylene, for example, is extremely hazardous because of its tendency to explode. A new process for preparing cytosine arabinoside has been discovered. Although the synthesis goes through the aminooxazoline intermediate, a separate isolation step of this intermediate is not required. Furthermore, a new cyanovinylating agent without the serious problems of the past agents has now been discovered. The invention also includes new methods for preparing the aminooxazoline and the cyanovinylating agent. BRIEF SUMMARY OF THE INVENTION A process for preparing cyclocytidine tosylate salt has been discovered which comprises: A. reacting D-arabinose with cyanamide or cyanide plus aqueous ammonia in an inert solvent to prepare the aminooxazoline of D-arabinose B. contacting the said aminooxazoline of Step a with cis-β- [trimethylammonium]-acrylonitrile tosylate. A further aspect of the invention is the preparation of the aminooxazoline of D-arabinose which comprises reacting D-arabinose with cyanamide in an inert, aprotic solvent in an essentially dry environment with catalytic quantities of a base present. A still further aspect of this invention is the preparation of the compound SPC1 Which comprises reacting the aminooxazoline of D-arabinose with cis-β-[trimethylammonium]-acrylonitrile tosylate. Another aspect of this invention is the selective preparation of the anion of cis-1-cyano-2-hydroxyethylene which comprises contacting isoxazole with a base of a strength equal to or greater than sodium methoxide which is in an inert organic solvent at a temperature less than or equal to -40°C. It has also been found that the temperature of the isoxazole at the time of the addition is critical. If isoxazole is at an ambient temperature, the -40°C. is essential for proper yields of the cis anion. However, if the isozazole is cooled prior to addition, the reaction solution may be maintained at a higher temperature. A further aspect of the invention is the compound cis-β-[trimethylammonium]-acrylonitrile tosylate. DETAILED DESCRIPTION OF THE INVENTION A similar pathway to cytosine arabinoside, through the aminooxazoline intermediate, is illustrated in the aforementioned Orgel and Sanchez patent. With regard to preparing the aminooxazoline of cytosine arabinoside, the disclosure of Orgel and Sanchez appearing at Column 4, line 63 to Column 6, line 11, is herein incorporated by reference. A new, more preferred method of preparing the aminooxazoline has been discovered. This method comprises reacting D-arabinose with cyanamide in an inert, aprotic solvent in an essentially dry environment with catalytic quantities of a base present to form the aminooxazoline of D-arabinose. Rather than working in an aqueous system, an essentially dry system is preferred. Consequently, cyanamide is preferred over the usually aqueous system of ammonia and cyanogen. Cyanamide can be obtained commercially as solid calcium cyanamide or as an aqueous solution of cyanamide. However, the calcium cyanamide can be converted to free cyanamide by the addition of hydrochloric acid followed by extractive purification. Anhydrous cyanamide can be additionally prepared by contacting aqueous cyanamide with calcium chloride followed by ethyl acetate extraction of cyanamide. The solvent employed in this reaction is preferably an inert aprotic, organic solvent such as dialkylamides and dialkylsulfoxides which are liquid at the reaction temperature. Examples of such solvents include dimethylformamide, dimethylacetamide, dimethylsulfoxide, diethylformamide, diethylacetamide and the like. For improved reaction yields of oxazoline and length of time of reaction, a catalytic quantity of base is preferred. Bases which can be employed are carbonates of metals such as potassium, lithium, and sodium; bicarbonates such as potassium, lithium and sodium; and ammonia. Organic bases such as pyridine, lutidine and triethylamine can also be used. The most preferred base is potassium bicarbonate. When using a solid material such as potassium bicarbonate, it is found to be preferable that it is micronized. A dry, free flowing material appears to provide better yields. The quantity of catalyst employed is from about 10-30 g./150 g. of D-arabinose when using a solid catalyst. If a liquid catalyst is employed, the quantity of catalyst is from about 0.1 to 1.0 mole equivalent of D-arabinose. The reaction can be conveniently carried out at a temperature of from about 30° to about 130°C. The lower end of the temperature range is somewhat dependent upon the reaction time. Oxazoline will be formed, but at a lower rate. The upper end of the temperature range is dependent upon the yield of oxazoline one desires. For example, as the temperature increases, oxazoline degrades more readily. The reaction time is dependent upon the temperature. However, it has been found that a reaction time of 75 minutes at a temperature of 90°C. brings about a good yield of oxazoline in a reasonable length of time. The oxazoline is now converted to the cyclocytidine salt by reaction with the cyanovinylating agent, cis-β-[trimethylammonium]-acrylonitrile tosylate. The oxazoline can be reacted directly with the acrylonitrile without isolation from its reaction vessel, if desired. Otherwise the oxazoline can be isolated by standard techniques of crystallization and then converted to the cyclocytidine salt by the cyanovinylation process. The cyanovinylation is carried out by reacting the aminooxazoline with cis-β-[trimethylammonium]-acrylonitrile tosylate. To obtain significant yields of the cyclocytidine salt, the reaction should be run in an inert, aprotic solvent such as the dialkylamides, for example, formamides, acetamides and other amides which are liquid at the reaction temperature. Examples of such solvents include dimethylformamide, dimethylacetamide, diethylformamide and the like. The length of time of the reaction is dependent upon the temperature. A temperature range of from about 30° to about 100°C. is generally satisfactory. A temperature range of from about 40° to about 60°C. brings about a good compromise between yield and length of the reaction. It is preferred to carry out this reaction in a flowing nitrogen atmosphere. Under these circumstances, the cyclocytidine salt is recovered as a white crystalline material. If an inert, mobile atmosphere such as nitrogen is not employed, the cyclocytidine salt is recovered as a yellow crystalline material. Analyses indicate these materials are the same. Although the reason for the observed color difference is not clear, it is believed that trimethylamine provides color to the crystals. If nitrogen is passed through the reaction vessel, the trimethylamine is driven off and white crystalline material is isolated. As in the Orgel and Sanchez patent, previously cited, the cyclocytidine salt is readily converted to cytosine arabinoside by contacting with a dilute base such as sodium hydroxide or aqueous ammonia at room temperature or a slightly elevated temperature, for example, from 25° to about 75°C. This results in an essentially quantative yield of cytosine arabinoside and side product tosic acid. These are readily separated on a strong acid resin such as a macroreticular resin, Dowex MSC-1. The cytosine arabinoside is then further purified in a conventional manner. The cis-β-[trimethylammonium]-acrylonitrile tosylate is prepared as follows: Isoxazole is selectively converted to the anion of cis-1-cyano-2-hydroxyethylene by contacting in an inert, aprotic solvent isoxazole with a base of strength greater than or equal to that of sodium methoxide at a temperature of less than or equal to about -40°C. As previously stated, the temperature of the isoxazole at the time of addition is critical. For example, if the isoxazole enters the reaction vessel at ambient temperature, the temperature in the vessel should be less than or equal to -40°C. However, if the isoxazole is cooled to -20°C. prior to entrance into the reaction vessel, the reaction temperature may be maintained at less than or equal to -20°C. Various combinations of isoxazole precooling and reaction vessel temperature maintenance are available for the selective production of the cis anion. The inert organic solvents are liquid at the reaction temperature. Examples of inert organic solvents are the ethers of two to eight carbon atoms, inclusive, and cyclic ethers of four to eight carbon atoms, inclusive. Examples of such solvents include diethyl ether, dipropyl ether, dimethylformamide, diethylacetamide and the like. Additional solvents which are appropriate include 1,2-dimethoxyethane and tetrahydrofuran. Examples of bases of appropriate strength are t-butoxide, t-amyloxide, isopropoxide, methoxide, ethoxide, and the like. Generally the cation is a metal such as sodium, potassium, lithium, etc. A preferred base solvent system is potassium tert-butoxide in tetrahydrofuran. The temperature may be as low as is consonant with a satisfactory reaction rate. Reaction temperatures significantly above -40°C., assuming essentially no precooling of isoxazole, should be avoided since trans isomer production occurs to an undesirable extent. The 1-cyano-2-hydroxyethylene anion is converted to a tosylate salt by standard reagents such as reaction with tosyl halide or tosyl anhydride. In order to maintain high yields, the temperature of the reaction should initially be maintained at a level less than or equal to the temperature used for the production of the cis anion. No additional solvent is necessary although a solvent in which the salt of 1-cyano-2-hydroxyethylene is soluble may be added. An example of such a solvent is acetonitrile. The by-products of the reaction are separated by extraction of the cis-β-tosyloxyacrylonitrile with an organic solvent such as ethyl acetate, toluene or benzene combined with aqueous base. After purification, the cis-β-tosyloxyacrylonitrile prepared above is now reacted with trimethylamine in a stereospecific reaction resulting in retention, thereby forming the cis-β-[trimethylammonium]acrylonitrile tosylate. The reaction temperature is generally from about +5° to about 50°C. The reaction can be carried out in the solvent employed in the previous extraction step for separating the by-products from the cis-β-tosyloxyacrylonitrile.

-

-