反应详情

4-Pyridinecarboxaldehyde oxime (30.6 g, 0.25 mol) was chlorinated in chloroform (350 ml) as described in Example 1 to produce N-hydroxy-4-pyridine-carboximidoyl chloride which was suspended in ether (500 ml) containing 2-chloroethanethiol (26.9 g, 0.25 mol). With ice bath cooling, triethylamine (5.1 g, 0.5 mol) was added dropwise. After the addition, water was made, the suspended solid, crude 2-chloroethyl N-hydroxy-4-pyridinecarboximidothioate was collected on a filter and dried. This crude ester was added to a solution of sodium ethoxide (from 5.75 g sodium in 500 ml ethanol), and the reaction mixture stirred for 4 hours. Water was added and the product was extracted with ether to give 5,6-dihydro-3-(4-pyridinyl)-1,4,2-oxathiazine, mp 80°-82° C., (found: C, 53.16; H, 4.56; N, 15.07. C8H8N2OS requires C, 53.33; H, 4.48; N, 15.55).