Trifluoroacetic acid → 2-(n-Butyl)-7-azaindole

Participants

Reaction Steps

A solution of 1-[2-(t-butoxycarbonylamino)pyridin-3-yl]hexan-2-one (42) (4.2 g) (prepared, e.g, as described in Preparation 29), in dichloromethane (25 ml) and trifluoroacetic acid (10 ml) was stirred at room temperature overnight. The solution was concentrated under vacuum and the residue was partitioned between aqueous ammonium hydroxide and ether. The ether layer was washed with brine, dried, and the solvent was evaporated. The residue was further purified by silica gel chromatography, eluting with 30% ethyl acetate-hexane, to give 2-(n-butyl)-7-azaindole (2.9 g), a compound of Formula (43), as an oil, which crystallized on standing to a solid, m.p. 46°-47° C.

Provenance & Evidence