- Process for the preparation of isothiocyanates
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There is disclosed a process for the preparation of isothiocyanates of formula STR1 wherein R1 and R2 are each independently of the other C1 -C6 alkyl and R3, R4 and R5 are each independently of the other hydrogen, halogen, C1 -C4 alkyl, C1 -C4 alkoxy, trifluoromethyl or nitro, which process comprises an amine of formula STR2 with ammonium thiocyanate or an alkali metal thiocyanate, in the presence of acid and an inert solvent, to the thiourea of formula STR3 and cleaving said thiourea by heating. The essential feature of this process consists in carrying out the reaction of the amine of the above formula with ammonium thiocyanate or an alkali metal thiocyanate in the presence of 0.5-5% by weight of water, based on the total weight of the reaction mixture. The isothiocyanates of the above formula are intermediates for the synthesis of pesticidal compounds.
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- Phenoxyphenylisothioureas, production thereof and use thereof in pest control, and phenoxyphenylthioureas as intermediates for the production of the phenoxyphenylisothioureas and use thereof in pest control
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The invention relates to N-phenoxyphenylisothioureas of the formula STR1 wherein each R1, R2 and R3 is hydrogen, halogen, C1 -C4 alkyl, C1 -C4 alkoxy, trifluoromethyl or nitro, each of R4 and R5 is C2 -C4 alkyl, R6 is C1 -C6 alkyl, C3 -C6 alkenyl or C3 -C5 alkynyl, R7 is C1 -C10 alkyl, C3 -C5 alkenyl or C3 -C6 cycloalkyl, and R8 is hydrogen or C1 -C10 alkyl. The invention further relates to the production of these compounds and their use in pest control, as well as to phenoxyphenylthioureas as intermediates for the production of the N-phenoxyphenylisothioureas of the invention.
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