Trifluoroacetic acid → HCID 178482105, compound

Participants

Reaction Steps

To 2-(4-aminophenyl)-5-(4-methoxyphenyl)-N-(2-thiazolyl)-imidazole-4-carboxamide (1.35 g) obtained in Example 48 were added ethyl orthoformate (40 ml) and trifluoroacetic acid (0.5 ml) and the mixture was refluxed under heating for one day. The reaction mixture was concentrated and to the residue were added tetrahydrofuran (40 ml) and ethyl alcohol (25 ml). Sodium borohydride (1.2 g) was added to the mixture with stirring. The mixture was stirred at room temperature for 1 hr and refluxed under heating for 2 hr. The reaction mixture was extracted with ethyl acetate, dried and concentrated. The obtained crude product was purified by silica gel column chromatography to give 5-(4-methoxyphenyl)-2-(4-methylaminophenyl)-N-(2-thiazolyl)-imidazole-4-carboxamide (0.6 g). This compound was dissolved in ethyl acetate and ether—hydrochloric acid was added to allow precipitation of the crystals of hydrochloride. The precipitated crystals were collected by filtration and recrystallized from methyl alcohol to give 5-(4-methoxyphenyl)-2-(4-methylaminophenyl)-N-(2-thiazolyl)-imidazole-4-carboxamide hydrochloride dihydrate (240 mg), melting point 193-197° C.

Provenance & Evidence