Acetic Anhydride → 5-Acetylamino-2-n-propylpyridine

Participants

Reaction Steps

A mixture of 5-amino-2-n-propylpyridine (example 23, step2) (62.7 g, 0.46 mol) and 45.7 g (0.483 mol) of acetic anhydride in 50 ml of acetic acid was refluxed for 3 hours in a nitrogen atmosphere. The mixture was evaporated and the oily residue was made slightly alkaline (pH=9.2) with a 10% sodium hydroxide solution. The precipitate was filtered off, and triturated with a mixture of water (1000 ml) and heptane (500 ml). The precipitate was filtered off, dried and resuspended in 400 ml of heptane. The resulting precipitate was filtered off and dried to yield 65.7 g (80%) of 5-acetylamino-2-n-propylpyridine. M.p. 122-24° C. 1H-NMR (CDCl3, 200 MHz) δ: 0.95 (t, 3H), 1.72 (sext, 2H), 2.20 (s, 3H), 2.73 (t, 2H), 7.10 (d, 1H), 7.70 (br s, 1H), 8.09 (dd, 1H), 8.43 (d, 1H).

Provenance & Evidence