反应详情

Sulfuric acid (940 g, 9.59 mol) was added over 30 min under ice cooling to a mixture of ethyl 3-(4-bromophenyl)-2-cyano-3-o-tolylpropanoate (200 g, 494 mmol) in acetic acid (1.06 kg, 17.7 mol), while keeping the internal temperature below 27° C., then the reaction mixture was heated at reflux for 20 h. After cooling to 40° C. ice (500 g) and ethyl acetate (1500 mL) were added, the precipitate collected by filtration and washed with water to produce the title compound (34.5 g). The filtrate was partitioned between ethyl acetate and water, the organic layer was washed with brine, dried over magnesium sulfate, filtered, and evaporated. The residue was stored in the refrigerator for 1 h. Then the precipitate was collected by filtration and washed with acetic acid and heptane to afford a second crop of product (96.2 g). Total yield: 130.7 g (83%). Off-white solid, MS: 319.0 [M−H]−.

1. customthe internal temperature below 27° C.
2. temperaturethe reaction mixture was heated
3. temperatureat reflux for 20 h
4. additionwere added
5. filtrationthe precipitate collected by filtration
6. washwashed with water