Patent GB-1393319-A (GB)
Title: Substituted crotonanilides and their use as herbicides
IPC: C07C319/14
Filed: 1973-09-26
Abstract: 1393319 Crotonanilides and their use as herbicides ROUSSEL UCLAF 26 Sept 1973 [26 Sept 1972] 45117/73 Heading C2C The invention comprises crotonanilides of the formula in which A represents a grouping of formula -ZR in which Z represents an oxygen or sulphur atom and R represents an alkyl radical containing from 1 to 6 carbon atoms or an aryl radical; X and Y which may be the same or different, each represent a hydrogen or halogen atom, an alkyl radical containing from 1 to 6 carbon atoms (which may, if desired, be substituted by one or more halogen atoms), an alkoxy group, in which the alkyl radical contains from 1 to 3 carbon atoms, an alkylthio or alkyl sulphinyl group in which the alkyl radical contains from 1 to 6 carbon atoms, an acyl radical containing from 1 to 6 carbon atoms, a nitro group or a trifluoromethyl radical; R 1  represents a hydrogen, chlorine or bromine atom, an alkyloxycarbonyl radical, in which the alkyl radical contains from 1 to 6 carbon atoms, a nitro group or an alkyl thio, alkylsulphinyl or alkylsulphonyl group, in which the alkyl radical contains from 1 to 3 carbon atoms; and R 2  represents an alkyl radical containing from 1 to 6 carbon atoms. The compounds of the invention are used as herbicides. The crotonanilides may be prepared by the following processes:- (a) compounds in which R 1  = H, R 2  = CH3 and A = ZR by reacting #-chlorocrotonyl chloride with a substituted aniline of formula to obtain a compound of formula which is treated with either an alkali metal alkylate or arylate or with an alkali metal thioalkylate or thioarylate; (b) compounds in which R 1  = COO-alkyl CO NO 2 , R 2  = CH 3  and A = OC 1  to C 6  alkyl by reacting a compound of formula with an alkyl orthoacetate of formula CH 3 - C(OR) 3 ; (c) compounds in which R = Cl, Br, alkylthio or alkylsulphinyl in which the alkyl radical contains from 1 to 3 carbon atoms, R 2  = CH 3  and A = OCH 3  by reacting a compound of formula with either diazomethane to obtain a compound wherein R 1  is Cl or Br or a sodium or potassium thioalkylate to obtain a compound of formula in which ale represents a C 1  to C 3  alkyl radical and treating this with methyl orthoformate to obtain the desired compound wherein R 1  = alkylthio in which the alkyl radical contains from 1 to 3 carbon atoms which is treated, if desired, with an oxidizing agent to obtain the compound in which R 1  = alkyl sulphinyl in which the alkyl radical contains from 1 to 3 carbon atoms, (d) compounds in which R 1  = alkylsulphonyl, R 2  = CH 3  and A = O C 1  to C 6  alkyl by reacting an isocyanate of formula with an alkyl sulphonyl acetone of formula alc-SO 2 CH 2 COCH 3  and treating the resulting compound of formula with an alkyl orthoformate of formula HC(OR) 3 . The compounds of the invention wherein R 1  is H, R 2 is C 1  to C 6  alkyl and Z is AR may also be prepared by reacting a compound of formula with (a) an O-alkylating agent to produce the desired compound wherein A is OR or (b) hydrogen sulphide in the presence of gaseous hydrogen chloride to produce a compound of formula which is treated with an S-alkylating agent to produce a compound wherein A is -SR.