Microwave-mediated synthesis of some novel heterocycles containing thiazole, oxazole, thiazine, oxazine, thiadiazine and triazolo-thiadiazine moiety

Abstract

5,5-Dimethyl cyclohexane-1,3-dione <b style="">1</b> has been brominated to yield 2-bromo-5,5-dimethyl cyclohexane-1,3-dione <b style="">2</b> which on further reaction with substituted thiocarbamides, carbamides, 2-aminothiophenols, 2-aminophenol, thiocarbohydrazones, thiosemicarbazones and triazoles has furnished 2-substituted imino-5,5-dimethyl-2,3,5,6 -tetrahydro-4<i style="">H</i>-benzothiazol-7-one <b style="">3</b>, 2-substituted imino-5,5-dimethyl-2,3,5,6-tetrahydro-4<i style="">H</i>-benzoxazol-7-one <b style="">4</b>, 7-substituted-2,2-dimethyl-2,3-dihydro-1<i style="">H</i>,10<i style="">H </i>-phenothiazin-4-one <b style="">5</b>, 2,2-dimethyl-2,3-dihydro-1<i style="">H</i>,10<i style="">H</i>-phenoxazin-4-one <b style="">6</b>, Schiff base of 2-hydrazino-6,6-dimethyl-6,7-dihydro-4<i style="">H</i>,5<i style="">H</i>-benzo[1,3,4]thiadiazine-8-one <b style="">7</b>, Schiff base of 2-amino-6,6-dimethyl-6,7-dihydro-4<i style="">H</i>,5<i style="">H</i>-benzo[1,3,4] thiadiazin-8-one <b style="">8</b> and 3-substituted alkyl-7,7-dimethyl-7,8-dihydro-5<i style="">H</i>,6<i style="">H</i>-1,2,4-triazolo[3,4-b][1,3,4]benzothiadiazin-9-one <b style="">9</b> respectively. All the final compounds have been synthesized by microwave irradiation as well as by conventional method.