Sodium hydride → 2-Methoxyethyl 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide

Beteiligte Stoffe

Reaktionsschritte

To a solution of 3.0 g. (0.015 mole) of N-methylsaccharin and 2.3 g. (0.015 mole) of 2-methoxyethyl chloroacetate in 15 ml. of dimethylsulfoxide at 40° C. was added 810 mg. (0.033 mole) of sodium hydride over a 2 hour period. The resulting reaction mixture was stirred for 2 hours at 40°-50° C. and was then quenched in 5% hydrochloric acid solution. The resulting suspension was extracted with methylene chloride (2×100 ml.) and the organic layers separated, combined and washed with water (50 ml.) and a brine solution (50 ml). The organic layer was dried over magnesium sulfate and concentrated to an oil, 4.1 g. The product was purified by dissolution of the residue in 5 ml. of acetone and addition of the acetone slowly to 125 ml. of 0.25 N hydrochloric acid. The suspension was allowed to stir for several hours, and was then filtered and dried 2.6 g. (55%). The product is indistinguishable from that reported in U.S. Patent Application Ser. No. 191,716, filed Sept. 29, 1980.

Herkunft & Nachweise