Acetaldehyde → HCID 178463263, compound

Participants

Reaction Steps

2-(4-Aminophenyl)-5-(4-methoxyphenyl)-N-(2-thiazolyl)-imidazole-4-carboxamide (1.0 g) obtained in Example 48 was dissolved in a mixed solvent of tetrahydrofuran and methanol, and added to a solution of 4N sulfuric acid (0.2 ml) and acetaldehyde (0.2 ml) in tetrahydrofuran. To the solution was added sodium borohydride (0.13 g) and the mixture was stirred at room temperature for 2 hr. To the reaction mixture was added a saturated aqueous sodium hydrogencarbonate solution and the mixture was extracted with ethyl acetate. The ethyl acetate phase was washed with saturated brine, dried and concentrated. The residue was purified by silica gel chromatography using, as a mobile phase, chloroform/ethyl acetate=100:1 to give 2-(4-ethylaminophenyl)-5-(4-methoxyphenyl)-N-(2-thiazolyl)imidazole-4-carboxamide (1.2 g). This was converted to hydrochloride to give 2-(4-ethylaminophenyl)-5-(4-methoxy-phenyl)-N-(2-thiazolyl)imidazole-4-carboxamide hydrochloride (0.48 g), melting point 250° C. or above.

Provenance & Evidence