Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Synthesis of 4-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)-6-phenyl-1,4-dihydro-2H-pyridazin-3-ones

Synthesis of... Chemistry of Heterocyclic Compounds, Vol. 39, No. 4, 2003 SYNTHESIS OF 4-(1,5-DIMETHYL-3-OXO- 2-PHENYL-2,3-DIHYDRO-1H-PYRAZOL-4-YLIMINO)- 6-PHENYL-1,4-DIHYDRO-2H-PYRIDAZIN-3-ONES A. E. Rubtsov and V. V. Zalesov Keywords: 3-imino-2-furanones, 4-imino-3-pyridazinones, substituted hydrazines. We have found that 1,5-dimethyl-4-(2-oxo-5-phenyl-3-furanylideneamino)-2-phenyl-1,2-dihydro-3- pyrazolone ( ) (the synthesis of was described in our previous work [1]) reacts with methyl-, ethyl-, and 1 1 phenylhydrazines or with 1,2-diphenylhydrazine in an inert solvent with recyclization to form 4-(1,5-dimethyl- 3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)-6-phenyl-1,4-dihydro-2H-pyridazin-3-ones 2: Ph Ph Ph O Ph 1 2 R NHNHR Me N Me N 1 – H O N Me Me O O 1 2a–c 1 1 2 2 2 2 a-c R = H, d R = Ph; a R = Me, b R = Et, c, d R = Ph The formation of compounds 2 probably proceeds through opening of the furan ring after attack of the hydrazine amino group at furanone C atom. The intermediate formed cyclizes through attack of the (2) secondary amino group –NHR at C atom with simultaneous splitting of water. A similar recyclization has 2 (5) been considered in the reactions of hydrazines with structurally-similar 4,5-disubstituted 2,3-furandiones [2, 3] and 3-methylene-(3H)-furan-2-ones [4]. Pyridazinones 2 are colorless crystalline compounds obtained in yields ranging from 64 to 92%. The http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Chemistry of Heterocyclic Compounds Springer Journals

Synthesis of 4-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)-6-phenyl-1,4-dihydro-2H-pyridazin-3-ones

Loading next page...
 
/lp/springer-journals/synthesis-of-4-1-5-dimethyl-3-oxo-2-phenyl-2-3-dihydro-1h-pyrazol-4-zVhhkunO05

References (2)

Publisher
Springer Journals
Copyright
Copyright © 2003 by Plenum Publishing Corporation
Subject
Chemistry; Organic Chemistry
ISSN
0009-3122
eISSN
1573-8353
DOI
10.1023/A:1024733917964
Publisher site
See Article on Publisher Site

Abstract

Chemistry of Heterocyclic Compounds, Vol. 39, No. 4, 2003 SYNTHESIS OF 4-(1,5-DIMETHYL-3-OXO- 2-PHENYL-2,3-DIHYDRO-1H-PYRAZOL-4-YLIMINO)- 6-PHENYL-1,4-DIHYDRO-2H-PYRIDAZIN-3-ONES A. E. Rubtsov and V. V. Zalesov Keywords: 3-imino-2-furanones, 4-imino-3-pyridazinones, substituted hydrazines. We have found that 1,5-dimethyl-4-(2-oxo-5-phenyl-3-furanylideneamino)-2-phenyl-1,2-dihydro-3- pyrazolone ( ) (the synthesis of was described in our previous work [1]) reacts with methyl-, ethyl-, and 1 1 phenylhydrazines or with 1,2-diphenylhydrazine in an inert solvent with recyclization to form 4-(1,5-dimethyl- 3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylimino)-6-phenyl-1,4-dihydro-2H-pyridazin-3-ones 2: Ph Ph Ph O Ph 1 2 R NHNHR Me N Me N 1 – H O N Me Me O O 1 2a–c 1 1 2 2 2 2 a-c R = H, d R = Ph; a R = Me, b R = Et, c, d R = Ph The formation of compounds 2 probably proceeds through opening of the furan ring after attack of the hydrazine amino group at furanone C atom. The intermediate formed cyclizes through attack of the (2) secondary amino group –NHR at C atom with simultaneous splitting of water. A similar recyclization has 2 (5) been considered in the reactions of hydrazines with structurally-similar 4,5-disubstituted 2,3-furandiones [2, 3] and 3-methylene-(3H)-furan-2-ones [4]. Pyridazinones 2 are colorless crystalline compounds obtained in yields ranging from 64 to 92%. The

Journal

Chemistry of Heterocyclic CompoundsSpringer Journals

Published: Oct 5, 2004

There are no references for this article.