1-(1,3,4-Thiadiazol-2-yl)-urea derivs as herbicides - and fungicides, prepd. from 2-amino-1,3,4-thiadiazoles

摘要

The prepn. of urea derivs. of formula (I): (where R 1-7C acyclic hydrocarbon radical opt. substd. by F, Cl and/or Br; R2 is a lower acyclic hydrocarbon radical or is phenyl opt. mono- or polysubstd. by one or more of Cl, Br, NO2, CF3, lower alkyl, lowr alkoxy or N(R5)2, where each R5 is lower alkyl; R3 is H or a lower acyclic hydrocarbon radical; R4 is a lower acyclic hydrocarbon radical) is carried out by reacting a cpd. of formula (II): with COCl2 in the presence of BF3 and reactive the product with R3R4NH. (I) can be used as selective herbicides (e.g. for pre-emergence use in maize crops), defoliants, desiccants, soil sterilants, and/or fungicides (no details given).