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

Temperature

50 °C

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.

1. temperatureThe mixture was heated at 50° C. for an additional 36 h
2. temperatureThe reaction was cooled to room temperature
3. temperatureThe reaction was heated to 80° C. for 1 h
4. temperaturecooled to room temperature
5. washwas washed successively with water and brine
6. dry with materialbefore being dried over sodium sulfate
7. filtrationThe solution was filtered
8. concentrationconcentrated in vacuo
9. customthe resulting crude oil was purified by flash chromatography
10. washeluting with a 80% hexanes/ethyl acetate mixture

ORD record

ord-a79b6788824d4746ab09d203036b98e2

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07714009B2