Potassium Carbonate → 2-Chloro-3-(propan-2-yl)pyridine

Acetone (1.1 mL, 14.89 mmol) was added to a stirred solution of 3-amino-2-chloropyridine 1 (1.662 g, 12.67 mmol) in 1,2-dichloroethane at room temperature. And then acetic acid (0.7 mL, 12.22 mmol) was added. After about 10 min, NaB(OAc)3H (3.005 g, 13.47 mmol) was added. The resulting mixture was stirred at room temperature for 24 h. More of acetone (5.5 ml) and NaB(OAc)3H (356 mg) and DCE (5 mL) were added. HOAc (0.35 mL) was added. After 2 h, MeOH (5 mL) was added. After overnight at room temperature, water was added to quench the reaction. Sat. aqueous potassium carbonate was added to neutralize the acid. The organic phase was separated and the aqueous was extracted with dichloromethane (2×20 mL). The combined organic solution was washed with brine, dried over Na2SO4, concentrated. The residue was separated by flash column chromatography on silica gel, eluting with 5-30% EtOAc/hexane to afford 1.20 g product as colorless oil, as well as 0.6326 g of starting material. 1H-NMR (CDCl3): 7.669 (dd, J=4.5-5.0 Hz and 1.5 Hz, 1 H, Ar—H), 7.075 (dd,J=8.0 Hz and 4.5-5.0 Hz, 1 H, Ar—H), 6.875 (dd, J=8.0 Hz and 1.5 Hz, 1 H, Ar—H), 4.194 (br, 1 H, NH), 3.644-3.578 (m, 1 H, CH), 1.260 (d, J=6.5 Hz, 6 H, 2 CH3). LC-MS: 171.1 (MH+).

1. waitAfter 2 h
2. waitAfter overnight at room temperature
3. customto quench
4. customthe reaction
5. customThe organic phase was separated
6. extractionthe aqueous was extracted with dichloromethane (2×20 mL)
7. washThe combined organic solution was washed with brine
8. dry with materialdried over Na2SO4
9. concentrationconcentrated
10. customThe residue was separated by flash column chromatography on silica gel
11. washeluting with 5-30% EtOAc/hexane

ORD record

ord-5934b8d3c6294600a63abd13e062246c

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09226970B2