Trifluoroacetic acid → HCID 68868585, compound

Participants

Reaction Conditions

Reaction Steps

(±)-(3-Benzyl-7-chloroquinoxalin-2-yl)-cyclopropyl-methylamine (16): To a stirred solution of 3-benzyl-7-chloro-2-cyanoquinoxaline (4.0 g, 14.3 mmol) in anhydrous CH2Cl2 (80 mL) at −64° C. under nitrogen was added dropwise cyclopropylmagnesium bromide (0.76 M in THF, 52 mL, 39.5 mmol). The reaction mixture was stirred at −68˜−30° C. for 40 min. It was cooled to −60° C. and TFA (12 mL) was added to the reaction mixture followed by NaBCNH3 (1.25 g, 18.9 mmol). The mixture was slowly warmed to −20° C. over 20 min, and then cooled to −30° C. and quenched with aq. NaHCO3 and extracted with CH2Cl2 (2×100 mL). The organic solution was washed with brine (60 mL), dried over MgSO4 and concentrated. Purification by flash column (SiO2, EtOAc/hexane MeOH/NH4OH 30:70:3:0.3) gave C-(3-Benzyl-7-chloro-quinoxalin-2-yl)-cyclopropyl-methylamine (16) as an oil (1.8 g). This oily product was slightly contaminated by impurities, but it was used directly for the next step without any further purification. 1H NMR (CDCl3) δ 8.02 (m, 1H), 7.96 (m, 1H), 7.67 (m, 1H), 7.19 (m, 5H), 4.52 (m, 1H), 4.41 (m, 2H), 1.37(m, 1H), 0.61 (m, 1H), 0.36 (m, 1H), 0.12 (m, 1H), 0.01 (m, 1H); MS (ESI), (M+H)+323.26, 325.26.

Provenance & Evidence