GB1368645A - Carboxylic acid imide halides and process for their preparation - Google Patents

Abstract

1368645 Carboxylic acid imide halides FARBWERKE HOECHST AG 31 Dec 1971 [31 Dec 1970] 61005/71 Heading C2C A substituted N-α-halogenomethyl carboxylic acid imide halide of Formula (I) where R represents a halogenated alkyl group of 1 to 4 carbon atoms or a phenyl radical which may be unsubstituted or substituted by one or more substituents, which may be the same or different, selected from alkyl groups having 1 to 3 carbon atoms, trifluoromethyl groups, alkoxy groups of 1 to 4 carbon atoms, halogen atoms nitro, phenyl, phenoxy, methylenedioxy groups, or the radical -C(Hal)=N-OH(R<SP>1</SP>)-Hal, R<SP>1</SP> represents a hydrogen atom, a halogenomethyl group or a phenyl group and Hal represents a chlorine or bromine atom, is prepared by: (a) reacting an amide of Formula (II) where R and R<SP>1</SP> have the same meaning as in Formula I, R<SP>2</SP> represents a halogen atom or hydroxyl group, and X stands for an oxygen atom, with a phosphorus pentahalide, or (b) reacting a thioamide of Formula II where R and R<SP>1</SP> have the same meanings as in Formula I, R<SP>2</SP> represents a hydroxyl group, and X represents a sulphur atom, first with a thionyl halide and then with chlorine or bromine. In the first step of process (b), 3H-1,2,4-dithiazole of Formula (III) is formed in a side reaction, which may be isolated as such or connected into the corresponding carboxylic acid imide, chloride or bromide of Formula (I) by means of chlorine or bromine.