Hydrochloric Acid → 2-(1-Hydroxaminoethyl)phenoxathiin

Participants

Reaction Conditions

Reaction Steps

The oxime from Step 1 (450 mg, 1.75 mmol) was suspended in ethanol (9 mL) and, at 0° C., there was added pyridine-borane (325 mg, 3.5 mmol) and 4M ethanolic hydrogen chloride (HCl) (1.33 mL, 5.32 mmol). The mixture was stirred at 0° C. for 20 minutes, then at room temperature for 1 hour. The ethanol was evaporated and the residue partitioned between water and ether. The aqueous portion was basified with 1N aqueous sodium hydroxide and extracted twice with ether. Drying of the ether and evaporation afforded the title product (408 mg) as an oil which slowly became a white solid, m.p.: 64°-67° C.

Provenance & Evidence