Treatment of 3-(2,4-dimethoxyphenylamino)- and 3-methylamino-1-phenylbut-2-en-1-ones with some benzenediazonium tetrafluoroborates gives, besides the usual azo coupling products [i.e., 3-(substituted imino)-1-phenylbutane-1,2-di-ones 2- (4-substituted phenylhydrazones) and 2-(4-methoxy-phenyldiazenyl)-3-methylamino-1-phenylbut-2-en-1-one, respectively], the previously unreported 1,4,5,6-tetrasubstituted pyridazinium tetrafluoroborates. The pyridazinium salts have been identified by X-ray analysis and by their H-1, C-13, N-15, B-11 and F-19 NMR spectra. Their formation is most probably the result of nucleophilic attack on the carbonyl carbon by the nitrogen of the hydrazone group and subsequent dehydration.
Formation of pyridazinium salts by azo coupling of N-substituted 3-amino-1-phenylbut-2-en-1-ones and diazonium salts
BERTOLASI, Valerio;
2004
Abstract
Treatment of 3-(2,4-dimethoxyphenylamino)- and 3-methylamino-1-phenylbut-2-en-1-ones with some benzenediazonium tetrafluoroborates gives, besides the usual azo coupling products [i.e., 3-(substituted imino)-1-phenylbutane-1,2-di-ones 2- (4-substituted phenylhydrazones) and 2-(4-methoxy-phenyldiazenyl)-3-methylamino-1-phenylbut-2-en-1-one, respectively], the previously unreported 1,4,5,6-tetrasubstituted pyridazinium tetrafluoroborates. The pyridazinium salts have been identified by X-ray analysis and by their H-1, C-13, N-15, B-11 and F-19 NMR spectra. Their formation is most probably the result of nucleophilic attack on the carbonyl carbon by the nitrogen of the hydrazone group and subsequent dehydration.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.