Triethylamine → Maleic Acid

Participants

Reaction Steps

A mixture of 4-methyl-5-[(2-aminoethyl)thiomethyl]imidazole dihydrochloride (0.5 g.), triethylamine (1 ml.) and 2-[2-(2,2,2-trifluoroethyl)guanidino]-(4-isothiocyanatobutyl)thiazole (0.5 g.) in tetrahydrofuran (15 ml.) was allowed to stand at room temperature overnight. The solution then was filtered, and the filtrate evaporated to dryness. The residue was purified by preparative thin layer chromatography using ethyl acetate/methanol/ammonia 6:1:1 v/v/v as developing solvent. The appropriate band was isolated and further purified by preparative thin layer chromatography using methanol/chloroform/ammonia 15:85:1 v/v/v as developing solvent. The appropriate band after extraction and evaporation yielded a brown gum. This was treated in acetone with excess maleic acid to give 1-[4-(2-[2-(2,2,2-trifluoroethyl)guanidino]thiazol-4-yl)butyl]-3-[2-([4-methylimidazol-5-yl]methylthio)ethyl]thiourea containing 2.25 equivalents of maleic acid. The n.m.r. spectrum in d6 dimethyl sulphoxide containing tetramethylsilane as internal standard (δ=0) included the following resonances (δ): 1.5 (multiplet, 4H); 2.25 (singlet, 3H); 2.5 (multiplet, 4H); 3.3 (multiplet, 4H); 3.8 (singlet, 2H); 4.1 (quartet, 2H); 6.45 (singlet, 1H); 8.8 (singlet, 1H).

Provenance & Evidence