GB855389A - Fungicidal compositions and basically substituted thiazoles for use therein - Google Patents

Abstract

The invention comprises thiazoles of the formulae: <FORM:0855389/IV(b)/1> and <FORM:0855389/IV(b)/2> where X is O or S; Y is H, alkyl, alkoxy or chlorine; Z is alkyl, alkoxy or chlorine; n is 2-4; R3 and R4 are H, C1-C6 alkyl or together form a ring; one of R5 and R6 is H and the other is acyl, carbalkoxy, carboxamide or N- substituted carboxamide; and R7 and R8 are C1-C6 alkyl. The compounds are prepared by reacting an alkali metal salt of the appropriate 2-hydroxy- or 2-meroapto-thiazole with an amine Hal-(Cn H2n). NR3 R4 or Hal-CH2-CH2-NR7R8, which may b liberated in situ from a salt thereof. In examples X is S, Y is H, Z is methyl, ethoxy or chlorine, Cn H2n is ethylene, propylene or trimethylene, NR3 R4 is amino, dimethylamino, diethylamino, di-isopropylamino, dibutylamino, ethyl-isopropylamino, ethyl-t-butylamino or morpholino, R5 is carbethoxy R6, is H and NR7 R8 is dimethylamino. The Specification also describes the preparation in the same way of other thiazoles having the general formula: <FORM:0855389/IV(b)/3> an which R1 and R2 are H, acyl, carbalkoxy, icarboxamido or N-substituted carboxamido or together form an aromatic hydrocarbon group which may be substituted by one or more alkyl, alkoxy or halogen substituents, and the other symbols are as before; the formula also includes 6 : 61-bis-benzthiazoles substituted in the 2 : 21-positions by -X-(Cn H2n) NR3 R4. Examples describe the preparation of benzthiazoles in which X is O or S, Cn H2n is ethylene, propylene or trimethylene and NR3 R4 is amino, dimethylamino, diethylamino, di-isopropylamino, ethyl-isopropylamino or ethyl-t-butylamino. Other compounds prepared are 2-(21-dimethylamino-ethylthio)-6-phenyl-benzthiazole, 2 : 21-bis-(21 dimethylamino - ethylthio) - 6 : 61-dibenzothiazole and 2-(21-diethylamino-ethylthio)-naphtho-[2,3]-thiazole. Starting materials are mentioned in which the benzthiazole nucleus is di- or poly-substituted. Ethyl 2-mercapto-thiazole-4-carboxylate is obtained from ethyl bromopyruvate and ammonium dithiocarbamate.ALSO:Fungicidal compositions comprise thiazoles of the formula: <FORM:0855389/VI/1> together with a finely-divided inert solid carrier or dispersed in an aqueous medium. In the formula R1 and R2 are H, acyl, carbalkoxy, carboxamide or N-substituted carboxamide, or together form an aromatic hydrocarbon group which may be substituted by halogen, alkyl or alkoxy; R3 and R4 are H or C1-C6 alkyl or together form a ring with the N atom; X is O or S; and n is 2-4; the formula also includes 6 : 61-bis-benzthiazoles substituted by the group -X(CnH2n) NR3R4 in the 2 : 21- positions. Suitable solid carriers are montmorillonite clays and talc, and a wetting agent can be incorporated in either the solid or the liquid compositions. The aqueous dispersions are prepared by diluting solutions in water-miscible solvents such as acetone.