反应详情

To an ice-cooled solution of methyl 1H-indazole-6-carboxylate (566 mg, 3.21 mmol) was added NaH (154 mg, 3.85 mmol), the mixture was then stirred at room temperature for 30 min. Methyl iodide (547 mg, 3.85 mmol) was added drop wise, and the reaction mixture was stirred overnight. Cooled to 0° C., added water and extracted with ethyl acetate. The organic phase was concentrated and purified by gel chromatograph to provide 130 mg of methyl 1-methyl-1H-indazole-6-carboxylate and 230 mg of methyl 2-methyl-2H-indazole-6-carboxylate, 59%. 1H NMR for methyl 1-methyl-1H-indazole-6-carboxylate: 1H NMR (400 MHz, CDCl3): δ 3.97 (3H, s), 4.14 (3H, s), 7.74-7.82 (2H, m), 8.02 (1H, s), 8.17 (1H, d, J=0.8 Hz). 1H NMR for methyl 2-methyl-2H-indazole-6-carboxylate: 1H NMR (400 MHz, CDCl3): δ 3.94 (3H, s), 4.25 (3H, s), 7.65-7.72 (2H, m), 7.92 (1H, s), 8.47 (1H, d, J=1.2 Hz). [M+H] Calc'd for C10H10N2O2, 191; Found, 191.

1. stirringthe reaction mixture was stirred overnight
2. temperatureCooled to 0° C.
3. extractionextracted with ethyl acetate
4. concentrationThe organic phase was concentrated
5. custompurified by gel chromatograph