反应详情

A mixture of Example 27D (11.6 g, 40 mmol) and dimethyl sulfate (20.2 g, 160 mmol) in toluene (10 mL) was heated in a microwave at 150° C. for 30 min. The mixture was concentrated and purified by flash chromatography (silica gel, MeOH/Et3N (10:1)/EtOAc in 10-60% gradient) to yield 6.6 g (54.4%) of the title compound. 1H NMR (300 MHz, DMSO-d6) ppm 0.41-0.53 (m, 4H), 1.15-1.27 (m, 1H), 1.38 (s, 9H), 3.98 (s, 3H), 4.20 (d, J=7.12 Hz, 2H), 6.70 (s, 1H); MS (ESI) m/z 304 [M+H]+, 302 M−H].

1. concentrationThe mixture was concentrated
2. custompurified by flash chromatography (silica gel, MeOH/Et3N (10:1)/EtOAc in 10-60% gradient)