Water → Benzyl (S)-2-(6-hydroxy-7-nitro-1H-indazol-1-yl)-1-methylethylcarbamate

Participants

Reaction Steps

A solution of the product from Step B (3.76 g, 9.3 mmol) in tetrahydrofuran (20 mL) and acetic acid (10 mL) was cooled in an ice bath, sodium nitrate (1.93 g, 27.9 mmol) was added and the reaction mixture was stirred for 1 h followed by warming to room temperature and stirring for one hour. Water (150 mL) was added to the reaction mixture, which was extracted with ethyl acetate (2×100 mL). The combined extracts were washed with a saturated aqueous solution of sodium bicarbonate (2×100 m), dried over magnesium sulfate, filtered, and evaporated to an oil (2.87 g). This residue was purified by chromatography (silica gel, hexane/ethyl acetate) to give a tan foam (2.44 g, 71%): LC/MS m/z 371. This was used in the next reaction without further purification.

Provenance & Evidence