Maleic Acid → 5-(4-Chlorobenzyl)-2-{4-[2-(2,2,2-trifluoroethyl)guanidinothiazol-4-yl]butylamino}pyrimid-4-one

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Reaction Steps

An intimate mixture of 2-[2-(2,2,2-trifluoroethyl)guanidino]-4-(4-aminobutyl)thiazole (0.39 g.) and 5-(4-chlorobenzyl)-2-methylthiopyrimid-4-one (0.39 g.) was heated at 150°-160° for 20 min. during which time effervescence occurred. The residue obtained on cooling was subjected to preparative thin layer chromatography using chloroform/methanol/ammonia 90:10:0.5 v/v/v for development. The appropriate zone of the chromatogram was isolated and extracted with hot ethanol/chloroform (50:50 v/v; 200 ml.). Evaporation of the eluate gave a glass which was dissolved in acetone (0.3 ml.) and treated with an excess of a saturated solution of maleic acid in acetone to give a maleate salt of 5-(4-chlorobenzyl)-2-{4-[2-(2,2,2-trifluoroethyl)guanidinothiazol-4-yl]butylamino}-pyrimid-4-one as a white powder (0.1 g.) which contained 1.5 moles of maleic acid and 1.5 moles of water of crystallisation. The n.m.r. spectrum in d6 dimethylsulphoxide using tetramethylsilane (δ=0) as internal standard included the following resonances (δ): 3.45 (2H, singlet); 4.1 (2H, multiplet); 7.1 (3H, singlet-maleic acid); 7.45 (1H, singlet) and 8.2 (4H, singlet).

Provenance & Evidence