| 摘要 |
A method for the preparation of a thiazine derivative of the formula <IMAGE> where each R is independently selected from hydrogen or a lower alkyl having 1 to 4 carbon atoms, the method comprising reacting together a sulphur donor which is selected from sulfur, ammonium or alkali metal sulfides, ammonium or alkali metal hydrosulfides, or hydrogen sulfide, 1,1-bis(methylthio)-2-nitroethene and a compound of the formula H2NCR2CR2CR2OSO3H where each R is as defined above. A preferred method is for the preparation of tetra-2-(nitromethylene)-2H-1,3-thiazine which possesses broad spectrum insecticidal activity, and is also useful as an intermediate in the synthesis of other insecticides.
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