反应详情

Phosphorous pentoxide (29.8 g, 210.2 mmol) was added to a suspension of 3-bromo-5-methylbenzamide (15.0 g, 70.1 mmol) in CHCl3 and the mixture was kept refluxing for 2 days (monitored by TLC). The reaction was allowed to cool to room temperature, and put into ice water under the condition of stirring. The organic layer was separated and the aqueous layer was extracted with dichloromethane (150 mL×2). The combined extracts were washed with brine, dried over NaSO4. The product, 3-bromo-5-methylbenzonitrile (7.20 g, 52%), was purified by flash column chomatography. 1H NMR (400 MHz, CDCl3) δ 7.60-7.56 (m, 2H), 7.40-7.39 (m, 1H), 2.39 (s, 3H).

1. temperaturethe mixture was kept refluxing for 2 days (monitored by TLC)
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted with dichloromethane (150 mL×2)
4. washThe combined extracts were washed with brine
5. dry with materialdried over NaSO4
6. customThe product, 3-bromo-5-methylbenzonitrile (7.20 g, 52%), was purified by flash column chomatography