Methyl iodide → Methyl 3-iodo-1-methyl-1H-indazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-iodo-1H-indazole-5-carboxylic acid methyl ester (1.0 g, 3.31 mmol) in THF (12 mL) at 0° C. was added KOt-Bu (520 mg, 4.63 mmol). The reaction mixture was stirred at 0° C. for 30 min then added iodomethane (0.29 mL, 4.63 mmol). Stirred at 0° C. for 30 min then warmed to room temperature and stirred for 2 h. The reaction was quenched with water and extracted with EtOAc (2×) then with CH2Cl2 (2×). The combined organics were dried over MgSO4 and concentrated to afford 950 mg of 3-iodo-1-methyl-1H-indazole-5-carboxylic acid methyl ester a pale yellow solid. NMR analysis revealed an 8:1 mixture of N1:N2 alkylated regioisomers. Major: 1H NMR (CDCl3, 300 MHz): δ (ppm) 8.25 (s, 1H), 8.13 (dd, J=8.7, 1.5 Hz, 1H), 7.39 (d, J=8.7 Hz, 1H), 4.13 (s, 3H), 3.98 (s, 3H).

Provenance & Evidence