Methyl chloroformate → HCID 58790151, compound

Participants

Reaction Steps

To a stirred solution of 349 (1.48 g, 9.1 mmol) in anhydrous THF (25 ml) at −78° C. under nitrogen was slowly added a solution of LDA (mono THF, 13.4 mL, 20.1 mmol, 1.5 M in cyclohexane). After 45 min, methyl chloroformate (776 μL, 10.0 mmol) was added. The mixture was warmed to room temperature over 2 h, and then stirred overnight. Then, the reaction mixture was quenched by addition of sat. ammonium chloride and extracted with AcOEt. After separation, the organic layer was successively washed with sat. NH4Cl, water, and brine. The aqueous phase was extracted twice with AcOEt. The combined organic layers were dried over anhydrous magnesium sulfate, filtered, and concentrated. The crude product was purified by flash column chromatography (eluents MeOH/CH2Cl2: 2/98 to 5/95) to afford title compound 350 (520 mg, 26% yield) as a pale yellow sticky solid. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 8.86 (d, J=2.5 Hz, 1H), 8.38 (dd, J=4.7, 1.4 Hz, 1H), 8.12-8.06 (m, 1H), 7.44 (dd, J=8.4, 4.7 Hz, 1H), 3.99-3.84 (m, 2H), 3.81 (t, J=8.8 Hz, 1H), 3.70 (s, 3H), 2.48-2.29 (m, 2H). MS (m/z): 221.0 (M+H)+−.

Provenance & Evidence