Ammonia → HCID 178525827, compound

Participants

Reaction Steps

4-{2-[3-(1-tert-Butoxycarbonylmethyl-piperidin-4-yl)-1H-indazol-6-yl]-(E)-vinyl}-piperidine-1-carboxylic acid tert-butyl ester (54.0 g) was added portionwise (ca. 9 portions) over 0.75 h to a stirred solution of 5M hydrochloric acid (270 ml) at 20°-25°, and the mixture was stirred at 20°-23° for 18 h. 880 Ammonia (54 ml) was added dropwise with caution over 0.75 h, maintaining the temperature between 18°-26°. The resulting solution (pH 1-2) was filtered through 1 micron graded glass fibre filter paper and the filter washed through with water (54 ml). Further 880 ammonia (36.2 ml) was added dropwise over 0.5 h maintaining the temperature between 22°-26° (pH 9-9.5). The suspension was stirred at 22°-230° for 3 h, and the resulting precipitate filtered off, washed with water (2×148 ml) and dried in vacuo to give the title compound as a white solid (27.6 g).

Provenance & Evidence