A New Synthetic Approach to Some Functionalized Cycl[3.2.2]azine Derivatives
摘要:
Dehydrogenation of some ethyl 4-oxo-1H-8,8a-dihydro-1,4-thiazino[3,4,5-cd]indolizine-1-carboxylates with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) were examined. No simply dehydrogenated products such as 4-oxo-1H- and 4-oxo-8H-1,4-thiazino[3,4,5-cd]indolizines or their full conjugated enol forms could be obtained, but ethyl cycl[3.2.2]azine-1-carboxylates were directly obtained via the cyclization and the subsequent desulfurization of the 4H-1,4-thiazine ring in the dehydrogenated intermediates.
DOI:
10.3987/com-10-s(e)72
作为产物:
描述:
二硫化碳 、 1-(ethoxycarbonylmethyl)-2-propylpyridinium bromide 、 硫酸二甲酯 在
base 作用下,
以30%的产率得到1-ethyl-(Z)-3--2(3H)-indolizinone
参考文献:
名称:
Preparation of New Nitrogen-Bridged Heterocycles. 46. Selective Formation of 4(1H)-8,8a-Dihydro-1,4-thiazino[3,4,5-cd]indolizinone and (E)-3-(1,3-Oxathiol-2-ylidene)-2(3H)-indolizinone Derivatives.
The reactions of 2-[mercapto(methylthio)methylene]-2(3H)-indolizinones with alkyl isothiocyanates in the presence of potassium t-butoxide in N,N-dimethylformamide afforded new heterocycles, 3-alkyl-2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithione derivatives, in moderate yields. On the other hand, their reactions with phenyl isothiocyanate did not afford the corresponding 2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithiones, although the reaction of 2-[mercapto(methylthio)methylene]-1-methyl-2(3H)-indolizinone with phenyl isothiocyanate gave 10-methyl-3-phenyl-2-phenylimino-2,3-dihydro-4H-1,3-oxazino[6,5-b]indolizine-4-thione in a very low yield (10%). The structures of these 2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithiones and the 2-phenylimino analogue were determined by inspections of their physical and spectral data and by a single crystal X-ray analysis of one of these compounds.