| 摘要 |
Process for the preparation of symmetrical diacylhydrazines having general formula (I): R1-CO-NH-NH-CO-R1 wherein R1 represents a linear or branched C1-C18 alkyl group; a linear or branched C2-C8 alkoxyalkyl group; a C2-C8 cyanoalkyl group; a C5-C8 cycloalkyl group, said cycloalkyl group optionally containing a heteroatom selected from oxygen, nitrogen and sulfur; a C6-C18 aryl group; a C7C20 arylalkyl group or alkylaryl group, said arylalkyl or alkylaryl groups optionally substituted with one or more hydroxyl groups, or with one or more linear or branched C1-C8 alkoxyl groups; comprising: (a) reacting an ester of a carboxylic acid having general formula (II): R1-CO-OR2 wherein R1 has the same meanings defined above and R2 represents a linear or branched C1-C18 alkyl group, with hydrazine, in its pure or hydrated state, obtaining a monoacylhydrazine having general formula (III): R1-CO-NH-NH2; (b) reacting the monoacylhydrazine having general formula (III) obtained in step (a), with a beta-ketoester having general formula (IV): R3-CO-CH2-COOR4 wherein R3 represents a linear or branched C1-C18 alkyl group, or a C6-C18 aryl group and R4 represents a linear or branched C1-C18 alkyl group, obtaining the desired symmetrical diacylhydrazine having general formula (I). |
