4-Butoxybenzoic acid → N-(7-chloro-1,8-naphthyridin-2-yl)-4-butoxybenzamide

Participants

Reaction Steps

The procedure is similar to that described in Example 1, but starting with 4-butoxybenzoic acid (15.5 g), N,N'-carbonyldiimidazole (12.9 g) and 2-amino-7-chloro-1,8-naphthyridine (8.9 g). The product produced by precipitation in water (approximately 18 g; m.p. 140° C.) is purified by chromatography on a column 40 mm in diameter charged with silica (200 g; 0.063-0.2 mm), using methylene chloride as eluant and collecting 60-cc fractions. After concentration to dryness of fractions 8 to 12 at 40° C. under reduced pressure (4 kPa), N-(7-chloro-1,8-naphthyridin-2-yl)-4-butoxybenzamide (6.2 g) is produced, m.p. 197° C.

Provenance & Evidence