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Synthesis of arylazopyrazolo[1,5‐ a ]pyrimidines and their application to synthetic fibres
Author(s) -
Rangnekar Dinesh W.,
Puro Sanjay S.
Publication year - 1990
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280490309
Subject(s) - morpholine , dyeing , chemistry , piperidine , hydrazine (antidepressant) , hydrate , yield (engineering) , pyridine , polyester , amide , pyrimidine , organic chemistry , nuclear chemistry , stereochemistry , materials science , chromatography , metallurgy
Abstract 4‐Phenyl‐5‐aminopyrazole 2 obtained from phenylcyanoacetaldehyde 1 and hydrazine hydrate reacted with diethyl malonate to give 3‐phenyl‐5,7‐dioxopyrazolo[1,5‐ a ]pyrimidine 3 , used as the key compound in the synthesis of arylazo dyes. The key compound 3 was coupled with various aryldiazonium salts 4 to yield 3‐phenyl‐7‐hydroxy‐6‐arylazopyrazolo[1,5‐a]pyrimid‐5‐ones 5. The resulting arylazo dyes (5) were refluxed in phosphorus oxychloride to give 3‐phenyl‐5,7‐dichloro‐6‐arylazo‐pyrazolo[1,5‐ a ]pyrimidines 6 , which subsequently reacted with refluxing morpholine and piperidine to yield 3‐phenyl‐5,7‐bis(morpholino and piperidino)‐6‐aryiazopyrazolo[1,5‐ a ]pyrimidines 7. The arylazo dyes 5 and 7 were applied to polyester fibres as disperse dyes and the arylazo dyes 6 were applied to polyamide fibres as disperse reactive dyes. The spectral and dyeing properties of the dyes were studied.