Hydrochloric Acid → 5,6-Dichloropyridin-2-amine

Temperature

87.5 °C

A mixture of N-(5,6-dichloropyridin-2-yl)pivalamide (790 mg, 3.20 mmol), hydrochloric acid, 37% (1.25 mL), water (1.25 mL), and EtOH (3 mL) was heated for 4 hrs in an oil bath at 85-90° C. LCMS showed nearly complete conversion to product. The reaction was cooled to room temperature and the reaction mixture was evaporated down to a small volume, then transferred to a separatory funnel where it was partitioned between aqueous sodium carbonate and ethyl acetate. The layers were separated, the aqueous phase was washed again with ethyl acetate, and the combined organic phases were washed with brine, dried over MgSO4, filtered, and evaporated to give a white solid. The material was subjected to a Biotage column in 20% ethyl acetate/hexane, collecting the main component. 5,6-Dichloropyridin-2-amine (0.49 g, 2.98 mmol, 93%) was obtained as a white solid. 1H NMR (500 MHz, CDCl3) δ ppm 7.44 (d, J=8.55 Hz, 1H), 6.36 (d, J=8.24 Hz, 1H), 4.58 (s, 2H). MS (LC/MS) R.T.=1.28; [M+H]+=164.8.

1. temperatureThe reaction was cooled to room temperature
2. customthe reaction mixture was evaporated down to a small volume
3. customtransferred to a separatory funnel
4. customwhere it was partitioned between aqueous sodium carbonate and ethyl acetate
5. customThe layers were separated
6. washthe aqueous phase was washed again with ethyl acetate
7. washthe combined organic phases were washed with brine
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. customevaporated
11. customto give a white solid
12. customcollecting the main component

ORD record

ord-ff13edcb3e0a4ffe9349ed91f62c3067

Source dataset

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08309577B2