| 摘要 |
1292383 Transesterification UGILOR 10 Feb 1970 [25 Feb 1969] 6370/70 Heading C2C Acrylates or methacrylates are prepared by the reaction between an acrylate or methacrylate and a higher alcohol containing at least three carbon atoms at between 60‹ and 150‹ C. in the presence of a titanium phenoxide catalyst. The preferred catalyst is of general formula in which R 1 and R 2 each represents a hydrogen atom, alkyl (1-4 C), alkoxy (1-4 C), aryl, alkenyl (1-4 C), amino, alkylamino (1-4 C) or a phenylamino groups and R 3 , R 4 , and R 5 have the same meaning as R 1 and R 2 but also may be hydroxyl group. The higher alkanol may be linear a branched and primary or secondary and many are listed. The phenoxides may have a stabilizing effect on the reaction and may be prepared by reaction of phenol on titanium tetrachloride or transesterification of alkyl titanates with the phenol as solvent. Many phenols are specified. The lower ester is preferably ethyl or methyl, and examples describe the preparation of butyl methacrylate, and acrylate, 2-ethyl hexyl acrylate, and lauryl methacrylate using various phenoxide catalysts, the preparation of one of which, tetramethoxyphenyl titanate, being described. |
