反应详情

A mixture of 3:1 ethanol-conc. HCl (200 mL) was cooled to 0° C. and then 3-nitrophthalic acid dimethyl ester (15.0 g, 62.8 mmol) was added. Maintaining the cooling, tin chloride (70.8 g, 314 mmol) was added portionwise, over a period of 15 minutes. Following completion of the addition, the cooling bath was removed, and stirring proceeded at room temperature. After 2 hours, the mixture was neutralized by the addition of solid sodium bicarbonate, and the resulting mixture was extracted with ethyl acetate (3×150 mL) and the combined extracts were washed with water (5×250 mL), were dried (MgSO4) and evaporated, providing 11.3 g of the product as a yellow oil in 86% yield: 1H NMR (CDCl3) δ 3.84 (s, 3H), 3.86 (s, 3H), 5.20 (br, 2H), 6.78 (dd, J=8.5 Hz, J=1.0 Hz, 1H), 6.90 (dd, 1H, J=7.3 Hz, J=1.0 Hz, 1H), 7.24 (t, J=7.8 Hz, 1H).

1. additionwas added portionwise, over a period of 15 minutes
2. additioncompletion of the addition
3. customthe cooling bath was removed
4. customproceeded at room temperature
5. additionthe mixture was neutralized by the addition of solid sodium bicarbonate
6. extractionthe resulting mixture was extracted with ethyl acetate (3×150 mL)
7. washthe combined extracts were washed with water (5×250 mL)
8. dry with materialwere dried (MgSO4)
9. customevaporated