Hydrochloric Acid → HCID 13324718, compound

Participants

Reaction Steps

A solution of 12.06 g (54.8 mmole) of 4-(1-indolinyl)benzonitrile of Example 2a in 62 ml tetrahydrofuran (THF) was added dropwise to a rapidly stirred ice cold solution of BH3 in THF (181 ml of 0.93M solution, 3.07 equiv. 168.4 mmole) under nitrogen. After heating at reflux for 1.5 hours, the solution was permitted to cool to room temperature and stand overnight. The ice cold reaction mixture was then treated dropwise with 6M aq. HCl (100 ml), heated at reflux for 40 minutes, cooled to 0° C., and made basic using solid NaOH. The resulting aqueous phase was extracted with ether and the combined organic portions (100 ml total) were washed with water (300 ml), twice with brine (300 ml portions) dried (Na2SO4) and concentrated to afford 13.2 g of crude free base. A solution of 7.5 g (33.4 mmole) of crude free base in 200 ml 1:1 ethanol-ether was treated with 50 ml of ethanolic HCl. 200 ml dry ether was added and the resulting solid was filtered, washed with dry ether, and dried thus giving 5.9 g (67.7%) of crude product. Recrystallization from hot ethanol-ether (charcoal) afforded 2.98 g of pure 4-(1-indolinyl)benzenemethanamine hydrochloride, m.p. 251.5°-252.5° C.

Provenance & Evidence