2-Hydrazinoethanol → methyl 1-(2-hydroxyethyl)-1H-indazole-7-carboxylate

Participants

Reaction Steps

A mixture of methyl 2-fluoro-3-formylbenzoate (3.6 g, 19.9 mmol) from Step C above and hydroxy ethyl hydrazine (1.5 g, 19.9 mmol) in MeOH (16 mL) was irradiated with microwaves at 150° C. for 1.5 h. The reaction mixture was cooled and partitioned between H2O and ethyl acetate. The aqueous phase was extracted with additional ethyl acetate and then the combined organic extracts were dried (Na2SO4) filtered, concentrated and purified by column chromatography (silica gel, 70:30 hexanes/ethyl acetate) to afford methyl 1-(2-hydroxyethyl)-1H-indazole-7-carboxylate as a yellow solid (2.83 g, 65%): 1H NMR (500 MHz, CDCl3) δ 8.13 (s, 1H), 7.99 (d, J=7.5 Hz, 1H), 7.94 (d, J=8.0 Hz, 1H); 7.18 (t, J=8.5 Hz, 1H), 4.84 (t, J=5.0 Hz, 2H), 4.13-4.07 (m, 2H), 3.99 (s, 3H), 3.20-3.10 (m, 1H).

Provenance & Evidence