Process and intermediates for the preparation of pyroxasulfone

An S-substituted thioisoxazole derivative the general Formula (III):

• wherein R is acetyl, dithiooxamoyl, 1-(N,N-dimethylmethanaminium) salt, sulfonyl salt, alkoxycarbonyl, 1-(1-phenylmethiminium),
• or being (5,5-dimethyl-4H-isoxazol-3-yl) benzenecarboximidothioate or a (5,5-dimethyl-4H-isoxazol-3-yl) benzenecarboximidothioate of:
• wherein X is chloride, bromide, difluoromethanesulfinate or methanesulfinate,
• or (5,5-dimethyl-4H-isoxazol-3-yl) 2-amino-2-thioxo-ethanimidothioate or (5,5-dimethyl-4H-isoxazol-3-yl) 2-amino-2-thioxo-ethanimidothioate of:
• wherein X is chloride, bromide, difluoromethanesulfinate and methanesulfinate,
• or 5,5-dimethyl-3-sulfosulfanyl-4H-isoxazole sodium salt:
• or 2-(5,5-dimethyl-4H-isoxazol-3-yl)-1,3-dimethyl-isothiourea or 2-(5,5-dimethyl-4H-isoxazol-3-yl)-1,3-dimethyl-isothiourea of:
• wherein X is chloride, bromide, difluoromethanesulfinate and methanesulfinate,
• or 2-(5,5-diethyl-4H-isoxazol-3-yl)-1,3-dimethyl-isothiourea or 2-(5,5-diethyl-4H-isoxazol-3-yl)-1,3-dimethyl-isothiourea of:
• wherein X is chloride, bromide, difluoromethanesulfinate and methanesulfinate,
• or 3-(4,5-dihydro-1H-imidazol-2-ylsulfanyl)-5,5-dimethyl-4H-isoxazole or 3-(4,5-dihydro-1H-imidazol-2-ylsulfanyl)-5,5-dimethyl-4H-isoxazole of:
• wherein X is chloride, bromide, difluoromethanesulfinate or methanesulfinate,
• or ethyl (5,5-dimethyl-4H-isoxazol-3-yl)sulfanylformate of:
• or S-(5,5-dimethyl-4H-isoxazol-3-yl) ethanethioate of:
• or N,N-dimethyl(5,5-dimethyl-4H-isoxazol-3-ylsulfanyl)methaniminium or N,N-dimethyl(5,5-dimethyl-4H-isoxazol-3-ylsulfanyl)methaniminium of:
• wherein X is chloride, bromide, difluoromethanesulfinate or methanesulfinate.