Hydrochloric Acid → HCID 86608551, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (2E,4E)-5-(5-dimethylaminobenzo[b]thiophen-2-yl)-penta-2,4-dienoic acid ethyl ester (540 mg, 1.8 mmol) in dry THF (10 mL) was added at 0° C. an aqueous solution of hydroxylamine (50%, 1.1 mL, 16.6 mmol). To this mixture was added a solution of potassium hydroxide in methanol (2.9 mL, 1M, 2.9 mmol) over a period of 40 minutes at 0° C. The mixture was stirred at 20° C. for 2 hours, and water (10 mL) was then added. The solution was acidified to pH 5 by addition of concentrated hydrochloric acid (10 M, CAUTION), then extracted with ethyl acetate (50 mL). The organic layer was washed with brine (25 mL), dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give a solid which was recrystallised from ethanol to give the title compound (367 mg, 71%) as an orange solid, mp 195° C. (decomp.).

Provenance & Evidence