Synthesis of spiro-fused (C5)-pyrazolino-(C6)-triazinones, a new heterocyclic system
摘要:
Reaction of 4-hydrazinoquinazoline with 2,4-diketoesters gives the corresponding 3-acylmethyl-2H[1,2,4]triazino[2,3-c]quinazolin-2-ones in a one-step procedure via cyclocondensation-Dimroth-like rearrangement. Spectroscopic studies as well as X-ray analysis reveal that the obtained triazinoquinazolines exist in their ketoimine tautomeric form. Treatment of these compounds with hydrazine hydrate affords 3'-(2-aminophenyl)-3-(het)aryl-spiro[pyrazoline-5,6'(1'H)-1,2,4-triazin]-5'(4'H)-ones or 5-(het)arylpyrazole-3-carboxylic acid hydrazides depending on the reaction conditions. The structure of the spiro-heterocycles was elucidated by means of single-crystal X-ray analysis and confirmed by spectroscopic investigations. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis of spiro-fused (C5)-pyrazolino-(C6)-triazinones, a new heterocyclic system
摘要:
Reaction of 4-hydrazinoquinazoline with 2,4-diketoesters gives the corresponding 3-acylmethyl-2H[1,2,4]triazino[2,3-c]quinazolin-2-ones in a one-step procedure via cyclocondensation-Dimroth-like rearrangement. Spectroscopic studies as well as X-ray analysis reveal that the obtained triazinoquinazolines exist in their ketoimine tautomeric form. Treatment of these compounds with hydrazine hydrate affords 3'-(2-aminophenyl)-3-(het)aryl-spiro[pyrazoline-5,6'(1'H)-1,2,4-triazin]-5'(4'H)-ones or 5-(het)arylpyrazole-3-carboxylic acid hydrazides depending on the reaction conditions. The structure of the spiro-heterocycles was elucidated by means of single-crystal X-ray analysis and confirmed by spectroscopic investigations. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis of spiro-fused (C5)-pyrazolino-(C6)-triazinones, a new heterocyclic system
作者:Alexander V. Karpenko、Sergey I. Kovalenko、Oleg V. Shishkin
DOI:10.1016/j.tet.2009.05.091
日期:2009.8
Reaction of 4-hydrazinoquinazoline with 2,4-diketoesters gives the corresponding 3-acylmethyl-2H[1,2,4]triazino[2,3-c]quinazolin-2-ones in a one-step procedure via cyclocondensation-Dimroth-like rearrangement. Spectroscopic studies as well as X-ray analysis reveal that the obtained triazinoquinazolines exist in their ketoimine tautomeric form. Treatment of these compounds with hydrazine hydrate affords 3'-(2-aminophenyl)-3-(het)aryl-spiro[pyrazoline-5,6'(1'H)-1,2,4-triazin]-5'(4'H)-ones or 5-(het)arylpyrazole-3-carboxylic acid hydrazides depending on the reaction conditions. The structure of the spiro-heterocycles was elucidated by means of single-crystal X-ray analysis and confirmed by spectroscopic investigations. (C) 2009 Elsevier Ltd. All rights reserved.