Maleic Acid → Maleic Acid

Participants

Reaction Steps

A mixture of 2-[2-(2,2,2-trifluoroethyl)-guanidino]-4-(4-aminobutyl)thiazole (0.12 g.) and 2-[2-(2,2,2-trifluoroethyl)guanidino]-4-[4-isothiocyanatobutyl]thiazole (0.12 g.) in methanol (3 ml.) was allowed to stand at room temperature overnight. The mixture was then evaporated to dryness and purified by preparative thin layer chromatography using methanol/chloroform/ammonia 85:15:1 v/v/v as developing solvent. The appropriate band was extracted with chloroform/ethanol 1:1 v/v (200 ml.) and the resulting solution evaporated to give a brown gum. This was treated in acetone with excess maleic acid to give 1,3-di[4-(2-[2-(2,2,2-trifluoroethyl)-guanidino]thiazol-4-yl)butylamino)thiourea containing 2.25 equivalents of maleic acid. The n.m.r. spectrum in d6 dimethylsulphoxide containing tetramethylsilane as internal standard (δ=0) included the following resonances (δ):-1.5 (multiplet, 8H); 3.3 (multiplet, 4H); 4.1 (quartet, 4H); 6.5 (singlet, 2H).

Provenance & Evidence