HCID 86750789, compound → HCID 19955598, compound

Participants

Reaction Steps

A mixture of (E)-methyl 2-benzyl-3-[2-butyl-4-chloro-1-[4-(2-isopropoxy-3,4-dioxocyclobut-1-en-1-yl)benzyl]-1H-imidazol-5-yl ]propenoate (1.2 g; preparable as described in Example 30(d)) and aqueous acetic acid (50%; 20 ml) was heated at 95°-100° C. for 6 hours. The solvents were evaporated under reduced pressure and the residue obtained was triturated with diethyl ether (2 ×20 ml). The resulting solid was dissolved in industrial methylated spirit (20 ml). Aqueous sodium hydroxide solution (0.5M, 22 ml) was added and the resulting mixture was stirred for 1 hour at ambient temperature and neutralised with hydrochloric acid (5M). The solvent was evaporated under reduced pressure and the residue obtained was extracted with aqueous sodium hydroxide solution (1M; 60 ml) and then acidified with hydrochloric acid (5M). The resulting precipitate was collected, washed with water (2×10 ml) and then dried to give (E)-2-benzyl-3-[2-butyl-4-chloro-1-[4-(2-hydroxy-3,4-dioxocyclobut-1 -en-1-yl)benzyl]-1H-imidazol-5-yl]propenoic acid, an active compound of the present invention, as a solid (0.54 g; m.p. 155°-160° C.).

Provenance & Evidence