Patent GB-1034485-A (GB)
Title: Production of 1,3,4-oxadiazoles
Inventor: WEIDINGER HANS
IPC: C07D413/04
Filed: 1963-04-30
Abstract: 1 - Aminoanthraquinone - 2 - carboxylichydrazine is reacted with benzoic piperidide chloride to give the red cotton dye 2-(1-amino-anthraquinonyl - (2)) - 5 - phenyl - 1,3,4 - oxadiazole; 1 aminoanthraquinone - 2 - carboxylic hydrazide is reacted with propionic piperidide chloride to yield 2 - (1 - aminoanthraquinonyl-(2)) - 5 - ethyl - 1,3,4 - oxadiazole; 1 - aminoanthraquinone - 2 - carboxylic hydrazide with N,N - dimethyl - formamide chloride gives red crystals of 2 - (1 - aminoanthraquinonyl -(2))-1,3,4-oxadiazole.ALSO:2-Substituted 1,3,4-oxadiazoles are prepared by reaction at a temperature between 20 DEG  and 200 DEG  C. in the presence of an alcohol and a teriary amine, of a N,N-disubstituted carboxylic amide chloride having the general formula:  <FORM:1034485/C2/1> in which R1 denotes a hydrogen atom, a C1 to C4 aliphatic hydrocarbon radical, a cycloaliphatic radical having 6 to 8 carbon atoms or an aryl radical which contains 6 to 16 carbon atoms and may bear an alkoxy group having 1 to 4 carbon atoms, a chlorine atom, a dialkyl amino group having one to four carbon atoms in each alkyl, a nitro group, and/or a quinone grouping, R2 and R3 may each denote an alkyl radical having 1 to 4 carbon atoms or the two alkyl radicals together with a nitrogen atom may form a 5 to 7-membered heterocyclic ring, together with a carboxylic hydrozide having the general formula:  <FORM:1034485/C2/2> in which R4 denotes an aliphatic radical having 1 to 7 carbon atoms, a cycloaliphatic radical having 6 to 8 carbon atoms, a piridine or an aryl radical which contains 6 to 16 carbon atoms and may bear an alkoxy group having 1 to 4 carbon atoms, a chlorine atom, a dialkyl amino group with 1 to 4 carbon atoms in each alkyl group, an amino group, a nitro group, or a quinone grouping and/or a carboxylic hydrozide. group. It is preferred to prepare the N,N-disubstituted carboxylic amide chloride in the reactor by treating the corresponding carboxylic amide with phosgene.  In the examples benzoic piperidide chloride is reacted with benzoic hydrazide to yield 2,5-diphenyl-1,3,4-oxadiazole; N,N-dimethyl-formamide chloride is reacted with p-nitrobenzoic hydrozide to give 2 - (4 - nitrophenyl) - 1,3,4 - oxadiazole; 1-aminoanthraquinone - 2 - carboxylic-hydrozide with benzoic piperidide chloride gives the red cotton dye 2-(1-aminoanthraquinonyl-(2))-5-phenyl-1,3,4-oxadiazole terephthalic dihydrazide is reacted with benzoic piperidide chloride to give 1,4 - di - (5 - phenyloxadiazalolyl - (2))-benzene; N,N - dimethyl - p - methoxybenzomide chloride is reacted with benzoic hydrazide to give 2-p-methoxyphenyl-5-phenyl-1,3,4 - oxadiazole; N,N - dimethylcylclohexene carboxylic amide chloride is reacted with benzoic hydrazide to yield 2-phenyl-5-cyclohexyl - 1,3,4 - oxadiazole; 1 - aminoanthraquinone-2-carboxylic hydrazide is reacted with propionic piperidide chloride to yield 2-(1-aminoanthraquinonyl - (2)) - 5 - ethyl - 1,3,4-oxadiazole benzoic piperidide chloride is reacted with isonicotinic hydrazide to give 2-pyridyl-5-phenyl-1,3,4-oxadiazole; acetic hydrazide is reacted with N,N-dimethyl acetamide chloride yielding 2,5-dimethyl-1,3,4-oxadiazole.