METHOD OF OBTAINING OF DIURETHANS

摘要

1467513 Aromatic diurethanes, their preparation and herbicidal applications SCHERING AB 26 Feb 1974 [1 March 1973] 8621/74 Heading C2C [Also in Division A5] The invention comprises compounds of general Formula I wherein R 1 represents an allyl, C 1-4 alkyl or halo-C 1-4 alkyl group; R 2 represents an allyl, alkynyl, C 1-4 alkyl, halo C 1-4 alkyl, cyclohexyl, benzyl or phenethyl group; R 3 represents a methyl or ethyl radical and X represents O or S, which may be prepared by reacting (a) a compound of Formula II or alkali metal salt thereof, with a carbamoyl chloride of formula optionally in the presence of a tertiary organic base at 0-100‹ C., (b) a compound of general Formula III in the presence of an acid binding agent, e.g. an inorganic or tertiary organic base, with an amine or (c) a nitrocompound of Formula IV by catalytic hydrogenation to form the corresponding amine which is then reacted with a compound of formula in the presence of an acid binding agent. Herbicidal compositions having especial application to the treatment of weeds associated with cotton crops comprise at least one compound of Formula I together with a carrier and optionally additional material(s) selected from fungicides, nematicides or other plant protecting or pest combating agents, fertilizers or surface active agents many of which materials are specified.