| 摘要 |
In the preparation of 1-(4-(N-dialkylaminoalkylsulphonamido)-phenyl)-3-(4-chlorophenyl)- DELTA <2>-p yrazolines and their protonation or quaternisation products by condensation of the corresponding 4-(N-dialkylaminoalkyl)sulphonamidophenylhydrazines with 4,ss-dichloropropiophenone, very good yields are obtained when crystalline 4-(N-dialkylaminoalkyl)sulphonamidophenylhydrazine-N<2>-sulphonic acids are hydrolysed by aqueous mineral acid to the corresponding free hydrazines and these are condensed in virtually homogeneous, alcoholic-aqueous medium at a pH of 1.5 to 6. The process products are useful optical brighteners for synthetic fibres.
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