GB929182A - Production of azoalkanes - Google Patents

Abstract

Polymerization catalysts comprise a ,a 1-di-substituted azoalkanes of general formula, <FORM:0929182/IV(a)/1> in which each A is a group N3, -O(O)CH, -O(O)CR111, -S(O)CR11, -S(S)CR11, -O(O)COR111, -S(O)COR11, -S(S)COR11, -CN, -OCN, -SCN or -SR11 and R, R1 and R11 are aliphatic, araliphatic, aromatic, cycloaliphatic or heterocyclic groups with not more than 22 carbon atoms, or R and R1 taken together with the carbon atom to which they are attached form a cycloaliphatic or heterocyclic group, and R111 is an aliphatic group derived from the acid R111COOH or R111O.CO.OH which is liquid at 40 DEG C., and when A is a cyano group or an alkane carboxylic group R is an aromatic group (see Group IV(b)) and their use in the copolymerization of styrene and methyl methacrylate is mentioned. They may be used as rubber blowing agents and as an aid to vulcanization.ALSO:The invention comprises a ,a 1-disubstituted azoalkanes of general formula <FORM:0929182/IV(a)/1> in which each A is a group -N3, -O(O)CH, -O(O)CR111, -S(O)CR11, -S(S)CR11, -O(O)COR111, -S(O)COR11, -S(S)COR11, -CN, -OCN, -SCN, or -SR11, and R, R1, and R11 are aliphatic, araliphatic, aromatic, cycloaliphatic or heterocyclic groups with not more than 22 carbon atoms, or R and R1 taken together with the carbon atom to which they are attached form a cycloaliphatic or heterocyclic group, and R111 is an aliphatic group derived from an acid R111.COOM, or R111O.CO.OM which is liquid at 40 DEG C. and when A is a cyano group or an alkane carboxylic group R is an aromatic group, which are prepared by reacting an a ,a 1-dihalo azoalkane, <FORM:0929182/IV(a)/2> in which Hal is a halogen atom at a temperature below 40 DEG C. with a substance YA, in which Y is a cation such as an alkali metal, alkaline earth metal, or ammonium cation, and which undergoes double decomposition with the a ,a 1-dihaloazoalkane in the presence of a halogen acceptor, in the presence of a polar solvent. In a modified preparation of the compound in which A is an acyloxy or mono-esterified carbonate group a solution of a ketazine, RR1C=N-N=CRR1, in solution in an acid of general formula A1.OH in which A1 is an acyloxy or mono-esterified carbonate group, the acid being liquid at 40 DEG C. or below, in the presence of an ammonium or metal salt of the acid. R, R1 and R11 may be substituted, e.g. with halogen, nitro and cyano groups. Examples describe the preparation of 2,21-di-(formyloxy)-, 2,21-di(acetoxy)-, 2,21-di-(capronoxy), 2,21-di-(acetylthio)-, 2,21-di-(thiocyanato)-, 2,21-di(ethylthio)-, 2,21-di-(ethoxythiocarbonylthio)-2,21-di-(phenylthio) -, 2,21-di-(2-benzothiazolylthio), 2,21-di-(azido)-, 2,21-di(cyano)-2,21-azo propane; 2,21-di-(acetoxy)-2,21-azobutane; 3,31-di-(acetoxy)-3,31-azopentane; 2,21-di- (acetoxy)- 4,41-di-(methyl)-2, 21-azopentane; 1,11-diacetoxy-1,11-di-(phenyl)-, 1,11-di-(ethoxythiocarbonylthio)-1,11-di-phenyl- and 1,11-di-(thiocyanato)-1,11-di-phenyl- 1, 11-azoethane; 1,11-di- (acetoxy)-1,11-azocyclopentane; and 1,11-di-(acetoxy)-, 1,11-di-(thiocyanato)- and 1,11-di-(phenylthio)-1,11-azocyclohexane; and 1,11-di-(propionyloxy)-1,11-azocyclooctane, and other compounds mentoned are 1,1,11,11-tetraphenyl-1,11-di(acetoxy)-, and 1,1,1111-tetracyclohexyl-1,11-di(phenylmercapto) -1,1 azomethanes, 1,11-di(cyclohexyl)- 1,11-di(acetoxy)-1, 11-azoethane, 2,21-di(benzoxy)- and 2,21-di(cyanato)-2,21-azopropane and 1,11-di(acetoxy)-1,11-azocycloheptane. The compounds may be used as medicaments, photosensitisers, polymerisation catalyst and blowing agents, fungicides plant growth regulants and bactericides.ALSO:Blowing agents for rubber comprise a , a 1-disubstited azoalkanes of general formula <FORM:0929182/V/1> in which each A is a group N3, -O(O)CH, -O(O)CR111, -S(O)CR11, -S(S)CR11, -O(O)COR111, -S(O)COR11, -S(S)COR11, -CN, -OCN, -SCN or -SR11 and R, R1 and R11 are aliphatic, araliphatic, aromatic, cycloaliphatic, or heterocyclic groups with not more than 22 carbon atoms, or R and R1 taken together with the carbon atom to which they are attached form a cycloaliphatic or heterocyclic group and R111 is an aliphatic group derived from an acid R111 COOH or R111 O COOH which is liquid at 40 DEG C. and when A is a cyano group or a carboxylic group R is an aromatic group. (Group IVb). 2, 21-di- (2- benzothiazolylthio)- ,2 21-azopropane is an example of a blowing agent which also acts as a catalyst for the vulcanisation of rubber.