Potassium Carbonate → 4-[(2-Methoxycarbonyl-2-methylpropionyloxy)-methoxy]-2-methyl-N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-Dioxide

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Reaction Steps

To a dry round bottomed flask equipped with a reflux condenser and stirring bar were added piroxicam (1.50 g, 4.53 mmol), potassium carbonate (1.24 g, 8.98 mmol), iodomethyl methyl 2,2-dimethylmalonate (1.48 g, 5.17 mmol) and dry acetone (15 mL). The heterogenous reaction mixture was heated to reflux under a nitrogen atmosphere for 3 hours. Chromatographed title product was isolated according to the method of Example 5, 0.95 g (43.2%) light yellow solid which was recrystallized from toluene-hexane to give light yellow crystals: mp 112°-114° C.; IR (KBr) 1690, 1680 cm-1 ; 1H NMR (CDCl3) delta 1.28 (s, 6H), 3.11 (s, 3H), 3.62 (s, 3H), 5.76 (s, 2H), 7.08-7.18 (m, 1H), 7.70-7.88 (m, 4H), 7.89-7.99 (dd, J=8 Hz, J=4 Hz, 1H), 7.30-7.44 (m, 2H), 9.42 (s, 1H); precise mass calcd for C22H23N3O6S m/e 489.1205, found 489.1230.

Provenance & Evidence