Hydrochloric Acid → Tert-butyl6-amino-2-chloro-4-methylnicotinate

Participants

Reaction Conditions

Reaction Steps

tert-butyl 2,6-dichloro-4-methylnicotinate (10.5 g, 40.1 mmol, 1 equiv), Pd2(dba)3 (1.84 g, 2.01 mmol, 0.05 equiv), xantphos (2.32 g, 4.01 mmol, 0.1 equiv), and Cs2CO3 slurried in dioxane (deoxygenated by bubbling nitrogen through it for 10 min) added. Benzophenone imine (8.0 mL, 48.1 mmol, 1.2 equiv) added and the mixture was heated at 90° C. for 1 h. Upon cooling to ambient temperature, the reaction was diluted with EtOAc and washed with water, dried (Na2SO4), and concentrated in vacuo. The crude product was taken up in MeOH (200 mL) and NaOAc (9.87, 120 mmol, equiv) and hydroxlamine hydrochloride (5.57 g, 80 mmol, 2 equiv) was added. After 30 min, the reaction was added to 1 N NaOH and extracted with DCM (×2). The combined DCM extracts were dried (Na2SO4) and concentrated in vacuo. The crude product was purified by flash column chromatography (0-30% EtOAc/hex) to afford tert-butyl 6-amino-2-chloro-4-methylnicotinate (7.5 g, 77%). 1H NMR (400 MHz, CDCl3) δ 6.22 (d, J=0.8 Hz, 1H), 4.58 (br. s., 2H), 2.27 (d, J=0.8 Hz, 3H), 1.60 (s, 9H); LCMS (ESI, M+1): 243.1.

Provenance & Evidence