反应详情

To a stirred suspension of methyl-3-amino-2-(methoxycarbonyl)benzoate (17.0 g, 81 mmol) in a mixture of concentrated HCl (44 ml) and water (440 ml) at 4° C. was added a solution of NaNO2 (6.73 g, 97 mmol) in water (25 ml) dropwise at 4-5° C. Stirring was continued for 30 min at 4° C. The mixture was then carefully neutralized with sat. sodium carbonate to pH 6. A stirred solution of CuCN (9.46 g, 105 mmol) and KCN (6.38 g, 105 mmol) in water (150 ml) was warned to 6° C. The cold neutralized diazonium solution was then added in small portions at a time with vigorous stirring. The mixture was stirred at 60° C. for 1 hour and then cooled to room temperature. The mixture was extracted with dichloromethane (4×150 ml) and the combined dichloromethane extracts were washed with water (2×100 ml), brine (100 ml) and dried. The solvent was removed in vacuo and the product was purified by chromatography (dichloromethane) to afford 12.36 g (65%) of the product as a light yellow solid: 1 H NMR (CDCl3) δ 8.19 (d, J=7.9 Hz, 1H), 7.8.9 (d, J=7.4 Hz, 1H), 7.64 (t, J=8.0 Hz, 1H), 4.03 (s, 3H), 3.94 (s, 3H).

1. customwas warned to 6° C
2. stirringThe mixture was stirred at 60° C. for 1 hour
3. extractionThe mixture was extracted with dichloromethane (4×150 ml)
4. washthe combined dichloromethane extracts were washed with water (2×100 ml), brine (100 ml)
5. customdried
6. customThe solvent was removed in vacuo
7. customthe product was purified by chromatography (dichloromethane)