Acetone → HCID 13506647, compound

Participants

Reaction Steps

To a round bottomed flask equipped with a reflux condenser and a stirring bar were added piroxicam (3.00 g, 9.1 mmol), potassium carbonate (2.50 g, 18.2 mmol), 3-bromophthalide (prepared according to U.K. Pat. No. 1,364,672; 2.51 g, 11.8 mmol) and acetone (45 mL). The heterogenous reaction mixture was heated to reflux under a nitrogen atmosphere. After 0.5 hour the solvent was removed in vacuo leaving a brown residue which was treated with water (200 mL) and methylene chloride (200 mL). The organic layer was separated and the aqueous layer extracted with additional methylene chloride (200 mL). The combined organic extracts were washed with water (200 mL), brine (200 mL), dried (Na2SO4) and concentrated in vacuo to a brown oil. Column chromatography on silica (1:9 ethyl acetate:methylene chloride) afforded a white foam which, when dissolved in hot toluene, precipitated within a few seconds as pure white crystals: 3.42 g (7.38 mmol, 81.5%); mp 151°-152° C.; IR (KBr) 1785, 1688 cm-1 ; 1H NMR (CDCl3) delta 3.13 (s, 3H), 6.97 (s, 1H), 7.07-7.35 (m, 1H), 7.58-8.18 (m, 9H), 8.30-8.44 (m, 2H), 9.18 (br s, 1H): precise mass calcd for C23H17N3O6S m/e 463.0855, found 463.0871.

Provenance & Evidence