反应详情

温度

17.5 °C

Compound 207 (7 g, 0.046 mol) was added to a mixture of concentrated hydrochloric acid (15.2 mL) and CH2Cl2 (60 mL). After cooling, ZnCl2 (18.6 g, 0.138 mol) was added at 15-20° C. The mixture was stirred at 15-20° C. for 0.5 h and cooled to 5-10° C. NaNO2 (9.5 g, 0.138 mol) was added portion wise while keeping the internal temperature 5-10° C. The reaction was continued for ˜2 h. The reaction mixture was poured into ice-water (50 mL). The organic layer was separated and the aqueous phase was extracted with CH2Cl2 (30 mL*2). The combined organic extracts were concentrated to afford crude product (4.2 g). The crude compound was suspended in hexane (20 mL), heated at 60° C. for 30 minutes and filtered. The filtrate was concentrated to afford the title compound R-2-2 (3.5 g, 44.4%) as an off-white solid. LCMS (m/z): 214.1[M+42]+. 1HNMR (400 MHz, CDCl3): δ 4.00 (s, 3H), 9.15 (s, 2H).

1. temperatureAfter cooling
2. temperaturecooled to 5-10° C
3. customthe internal temperature 5-10° C
4. waitThe reaction was continued for ˜2 h
5. customThe organic layer was separated
6. extractionthe aqueous phase was extracted with CH2Cl2 (30 mL*2)
7. concentrationThe combined organic extracts were concentrated
8. customto afford crude product (4.2 g)
9. temperatureheated at 60° C. for 30 minutes
10. filtrationfiltered
11. concentrationThe filtrate was concentrated