Propanal → 2-Chloro-N,N-dipropylpyridin-4-amine

Participants

Reaction Conditions

Reaction Steps

A mixture of 0.65 g (5.1 mmol) of 4-amino-2-chloropyridine and 1.8 mL (25 mmol) of propionaldehyde in 5 mL of dichloroethane was treated with two drops of glacial acetic acid and 3.2 g (15 mmol) of sodium triacetoxyborohydride. The mixture was heated to 50° C. for 1 h and an additional 0.9 mL (12.5 mmol) of propionaldehyde and 1.6 g (7.5 mmol) of sodium triacetoxyborohydride was added. The mixture was heated at 50° C. for an additional 36 h. The reaction was cooled to room temperature and 0.15 g (4 mmol) of sodium borohydride was added. The reaction was heated to 80° C. for 1 h and cooled to room temperature. The mixture was diluted with dichloromethane and was washed successively with water and brine before being dried over sodium sulfate. The solution was filtered, concentrated in vacuo and the resulting crude oil was purified by flash chromatography eluting with a 80% hexanes/ethyl acetate mixture to give 0.41 g (38%) of the title compound as a colorless oil.

Provenance & Evidence