Sodium hydride → nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetic acid

Participants

Reaction Steps

A solution of 100 g of 2-(methylthio)ethanol in dry tetrahydrofuran was added slowly to a solution of 6.0 g of sodium hydride (57% in mineral oil) in dry tetrahydrofuran at 0°. The mixture was then allowed to warm to room temperature and 13.1 g of methyl nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetate (1A), prepared as described in U.S. Pat. No. 3,962,234, was added, and the mixture was allowed to stand overnight at room temperature. The solvent then was evaporated under reduced pressure, the residue was poured into water and the mixture was extracted with ether. The separated aqueous phase was acidified with acetic acid, and the product was extracted with methylene chloride. The extract was dried (MgSO4), decolorized, and the solvent was evaporated under reduced pressure. The residue was washed with pentane, then crystallized from ether and recrystallized from isopropyl alcohol to give the 2-(methylthio)ethyl ester of nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetic acid (1B), as a pale yellow solid, m.p.: 72°-73°.

Provenance & Evidence