Production of reactive free radicals and novel dibenzyl compounds

摘要

Initiators for the polymerization of ethylenically unsaturated monomers at 100-400 DEG C. have the formula wherein Y is H, C1- 6-alkyl, halogen, phenyl, MeO or EtO, R is H, Me, Et or Y-substituted phenyl, R1 is MeO, EtO or acetoxy and R2 is H, MeO, EtO or acetoxy. In examples, N-vinyl - 5 - methoxyazolidone is polymerized, using as initiator a ,a 1-diphenylbibenzyl or a ,a 1-diacetoxy-a ,a 1-dimethylbibenzyl. Also mentioned are the polymerization and copolymerization of styrene, acrylic compounds, vinyl chloride, isoprene and divinylbenzene, as well as the polymerization of aldehydes.ALSO:The invention comprises compounds of formula wherein Y is H, C1- 6-alkyl, halogen, phenyl, MeO or EtO, R is H, Me, Et or Y-substituted phenyl, R1 is MeO or EtO and R2 is H. In examples: (1) a -methoxy-a ,a 1-diphenylbibenzyl was obtained by reacting diphenylmethane with benzhydryl methyl ether (a) and t-Bu2O2 (b); (2) a ,a 1 - dimethoxy - a ,a 1 - diphenylbibenzyl was obtained from (a) and (b); (3) 4,41-di-t.-butyl - a ,a 1 - dimethoxy - a ,a 1 - dimethylbibenzyl from 4 - t.-butyl - a - methylbenzyl methyl ether and (b); (4) a ,a 1-dimethoxy-a ,a 1-dimethylbibenzyl from methyl a -methylbenzyl ether and (b); (5) a ,a 1 - dimethoxybibenzyl by methylating hydrobenzoin with MeI/Ag2O; (6) a ,a 1-diacetoxy - a ,a 1 - dimethylbibenzyl from a ,a 1-dimethylhydrobenzoin and ketene; (7) a ,a 1-diacetoxy - 4,41 - dichloro - a ,a 1 - dimethylbibenzyl from 4,41-dichloro-a ,a 1-dimethylhydrobenzoin and ketene. Compounds of the above formula wherein Y and R have the meanings given above, but R1 may alternatively be acetoxy and R2 may alternatively be MeO, EtO or acetoxy, are used to initiate free radical chain reactions at 100 DEG to 400 DEG C., e.g. addition of a non-tertiary alkanol to an a -olefin or of a cycloalkane to formaldehyde. In examples: (9) 2-methyl-2-decanol is obtained from 1-octene and isopropyl alcohol, and (10) cyclohexylcarbinol from cyclohexane and paraformaldehyde, using the product of Example (4) as initiator. Other reactions mentioned are formation of benzyl halide by halogenating toluene and the addition to olefins of non-tertiary amines or mercaptans; polyhalides (e.g. BrCCl3, CCl4), aldehydes and hypohalites.