Sulfur Dioxide → HCID 18357855, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of the product from Step D (1.73 g, 7.42 mmol) in THF (15 mL) cooled to -60° C. was added via syringe n-butyllithium in hexane (2.5 M, 3.56 mL, 8.91 mmol) over 5 min. After the addition was completed, the mixture was warmed to 0° C. and stirred for 20 min. The mixture was re-cooled to -60° C. and a stream of sulfur dioxide was passed through the surface of the mixture for 20 min. The mixture was warmed to ambient temperature and the volatiles were evaporated. To the residue was added sodium acetate trihydrate (3.03 g, 22.3 mmol) and water (50 mL) and the mixture was cooled to 0° C. Hydroxylamine-O-sulfonic acid (1.51 g, 13.4 mmol) was added and the mixture was allowed to stir for 30 min. The reaction mixture was extracted with ethyl acetate (3×100 mL), dried over molecular sieves and concentrated to give an orange oil (2.25 g) which solidified on standing. The solid was crystallized from methanol-methylene chloride to give a colorless solid (1.21 g, 52%, first crop): mp 161°-162° C.

Provenance & Evidence