合成路线1

A new synthesis for edatrexate has been described: The reaction of 2,4-diamino-6-(bromomethyl)pteridine (I) with tributylphosphine (II) in DMSO gives the corresponding phosphonium salt (III), which is condensed wtih 4-propionylbenzoic acid methyl ester (IV) by means of NaH in DMSO, affording 4-[1-(2,4-diaminopteridin-6-yl)-1-ethylvinyl]benzoic acid methyl ester (V). The hydrogenation of (V) with H2 and PtO2 in acetic acid gives 4-[1-(2,4-diamino-6,7-dihydropteridin-6-ylmethyl)propyl]benzoic acid methyl ester (VI), which, without isolation, is dehydrogenated with H2O2 in the same solvent yielding 4-[1-(2,4-diaminopteridin-6-ylmethyl)propyl]benzoic acid methyl ester (VII). The hydrolysis of (VII) with NaOH in DMSO - water affords the corresponding free acid (VIII), which is condensed with L-glutamic acid diethyl ester (IX) by means of isobutoxycarbonylchloride and triethylamine in DMF, giving edatrexate diethyl ester (X). Finally, this compound is hydrolyzed with NaOH in methanol.

合成路线2

Carboxilic acid (I) is converted to the correspondig acid chloride (II) and and amidated with dimethyl homoglutamate (III) to give the amide (IV). The benzyloxycarbonyl grouo of the amide (IV) is removed with H2 over Pd/C to give the amide (V), which is effectively alkylated with 6-(bromomethyl)-2,4-diaminopteridine (VI) to produce compound (VII). Finally, compound (VII) is hydrolyzed with 1N NaoH to yield MX-68.

合成路线3

As shown in Scheme 22540502a, initially, starting material (I) is converted to benzothiazol (II) by treatment of sodium thiocyanate in the presence of bromine. Alkali hydrolysis of compound (II) gives thiol (III), which is immediatly submitted to S-alkylation with 1-bromo-2-chloroethane, followed by acid esterification, which gives thioether (IV). After protection of the amino group of compound (IV) with tosyl chloride, treatment of NaOH affords benzothiazine ester (V), and next hydrolysis produces the key intermediate (VI). Subsequently, compound (VI) is converted to the corresponding acid chloride and amidated with dimethyl homoglutamate to give the amide (VII). The tosyl group of the amide (VII) is removed with HBr-AcOH to give the amine (VIII), which is effectively alkilated with 6-(bromomethyl)-,4-diaminopteridine (IX) to produce (X). Finally, compound (X) is hydrolyzed with 1N NaOH to yield MX-68.

合成路线4

The synthetic scheme of tritiated MX-68 ia also presented in Scheme 22540503a. Treatment of compound (I) with triphenylphosphine, followed by Wittig reaction with 4-ethylbenzoic aldehyde (II) yields an olefin (III). To improve the solubility of (III) in routine organic solvents, the amino group of compound (III) is acylated with anhydride (IV) to give a lipophilic olefin (V). The olefin moiety is next oxidized by treatment of ozone to give an aldehyde (VI). Reduction of compound (VI) with NaBT4 is performed in isopropanol to give the corresponding tritiated alcohol (VII). The alohol (VII) is deacylated to yield acyl-free pteridine (VIII). The conversion of compound (VIII) to HBr salt, followed by bromination of alcohol with dibromotriphenylphosphorane, amination with compound (IX) and alkali hydrolysis produces [9-3H]-MX-68.

合成路线5

The first synthetic method started from 2,4-diamino-6-(hydroxymethyl)-pteridine (V). Conversion of (V) into the corresponding bromide (VI) was achieved by treatment with triphenylphosphine dibromide. Ylide (VII) was then prepared by reaction of bromide (VI) with triphenylphosphine, followed by deprotonation using potassium tert-butoxide. Wittig reaction between ylide (VII) and aldehyde (IV) produced the olefin (VIII), assumed to be a mixture of geometric isomers. Catalytic hydrogenation of olefin (VIII), followed by reoxidation of the pteridine ring with H2O2, yielded (IX). Finally, hydrolysis of (IX) with NaOH gave rise to the title compound.

合成路线6