THE PARTITION PRINCIPLE AS APPLIED TO THE STRUCTURE OF ENOLIC SODIUM DERIVATIVES OF 1,3-DIKETONES AND BETA-KETO ESTERS. II1

1932 ◽  
Vol 54 (1) ◽  
pp. 387-397 ◽  
Author(s):  
Arthur Michael ◽  
John Ross
2009 ◽  
Vol 2009 (23) ◽  
pp. 3467-3474 ◽  
Author(s):  
Oxana Kotova ◽  
Sergey Semenov ◽  
Svetlana Eliseeva ◽  
Sergey Troyanov ◽  
Konstantin Lyssenko ◽  
...  

1957 ◽  
Vol 0 (0) ◽  
pp. 2338-2340 ◽  
Author(s):  
E. M. Philbin ◽  
E. R. Stuart ◽  
R. F. Timoney ◽  
T. S. Wheeler
Keyword(s):  

2006 ◽  
Vol 60 (5) ◽  
Author(s):  
M. Awas

Abstract5-Acetyl-4,5-dihydro-1-phenylpyrazolo[3,4-d]pyrimidin-4-one was prepared and subjected to various chemical transformations to give novel 5-heterocyclic pyrazolopyrimidinone derivatives of expected important biological activity. Then, the latter compounds were used to obtain β-keto ester and α,β-unsaturated carbonylpyrazolopyrimidinones which were used as alternate precursors to produce new pyrazolopyrimidinones substituted with five-membered heterocycles such as pyrazole and isoxazole. The structure of these compounds was identified on the basis of their chemical behaviour as well as elemental and spectral analysis.


2020 ◽  
Vol 07 ◽  
Author(s):  
Dhanaji V. Jawale ◽  
Devendra Wagare ◽  
Dinesh L. Lingampalle ◽  
Prashant D. Netankar

Background: 1,4-benzothiazine carboxylates show wide application in the field of medicinal chemistry. Therefore, we have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Objective: Synthesis of 1,4-benzothiazine carboxylates and its guanidines by simple and facile method using efficient catalyst. Method: Derivatives of 1,4-benzothiazine carboxylates were synthesized by cyclocondensing β-keto esters with 2- aminobenzenethiols using CAN as a catalyst at room temperature. 1,4-benzothiazine caboxylate,condensed with guanidine hydrochloride in the presence of sodium methoxide in DMF to obtained new 3-substituted-l-4Hbenzo[b][1,4]thiazine-2-carboxyguanidines (88-91%). Results: All the products were obtained with good to excellent yields within 40 min. Here, CAN oxidizes aminothiophenol into disulfide and then nucleophilic attack of enolic form of β-ketoesters on the disulphide and 1, 4-benzothiazine acetates, were obtained with good yields. Conclusion: We have designed convenient and efficient method for the synthesis of 1,4-benzothiazine carboxylates. Most remarkable features of this cyclocondensation such as use of efficient catalyst and non-volatile solvent under mild reaction condition to obtained excellent yield.


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