Hydrochloric Acid → 8-Bromo-4,5-dihydrobenzo[2,3]oxepino[4,5-d]thiazole-2-carboxylic acid

Participants

Reaction Steps

To a solution of 8-bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulene-2-carboxylic acid ethyl ester from Example 21 (518 mg) in tetrahydrofuran (10 ml) was added a solution of sodium hydroxide (117 mg) in water (2 mL). Methanol (5 mL) was also added to aid dissolution. After 2 hours, the reaction mixture was acidified with HCl (2M) and the reaction mixture was then extracted with dichloromethane, dried (MgSO4) and the solvent removed in vacuo to yield 8-bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulene-2-carboxylic acid.

Provenance & Evidence