GB1391515A - Herbicidal compositions based on 1,2,3-thiadiazol-5-yl ureas - Google Patents

Abstract

1391515 4-Substituted-i ,2,3-thiadiazol-5-yI Ureas FMC CORP 22 June 1972 [23 June 1971 27 March 1972] 29204/72 Heading C2C The invention comprises herbicidal compounds of formula where A is a C 1 -C 4 alkyl or alkenyl radical; B is H or CH 3 but where A is other than CH 3 B is H; X is O or S; Y is -OR, -NHR , -NRR<SP>1</SP>, -NH-NH 2 or in which R<SP>1</SP> and R, which may be the same or different, are alkyl, alkenyl, alkynyl or cycloalkyl groups containing up to 12 carbon atoms and may also contain an ether linkage or a hydroxy substituent; Z is -O-, -CH 2 - or absent; and the metallic and amine salts thereof. These may be prepared by (a) aminolysis of phenyl (thiadiazol-5-yl) carbamates substituted in the 4-position with -COOR, e.g. to replace NHCOOPh by NHCON(CH 3 ) 2 ; (b) further aminating such products to replace COOR by CONHR or CONRR<SP>1</SP>; (c) ester interchange of products of (a); and (d) reacting a 4-carbonyl chloride with YH. Thioureas may be prepared by reaction of the corresponding urea with phosphorus pentasulphide, and the salts prepared by reaction with the corresponding base. Herbicidal compositions containing compounds of the invention are particularly effective in the presence of crops such as corn and peanuts. Phenyl (4-alkoxycarbonyl. 1 ,2,3-thiadiazol-5- yl)-carbamates are prepared by reaction of phenyl chloroformate with KSCN and an alkyl diazoacetate. 1,1 - Dimethyl - 3 - (4 - carboxy - 1,2,3- thiadiazol - 5 - yl) - urea was prepared by hydrolysis of its ethyl ester, and was converted to its acid chloride by reaction with 50C1 2 .