Please use this identifier to cite or link to this item:
http://nopr.niscair.res.in/handle/123456789/1419
Title: | p-TsOH Catalyzed regioselective synthesis of 8,8'-methylene-bis-4- oxo-dihydrochromeno [4,3-c]pyrazoles |
Authors: | Reddy, Ch Sanjeeva Nagaraj, A |
Keywords: | p-TsOH, regioselective synthesis;8,8'-methylene-bis-4-oxo-1,4-dihydrochromeno[4,3-c]pyrazoles;8,8-methylene-bis-2,4-dihydrochromeno[4,3-c]pyrazoles |
Issue Date: | Feb-2008 |
Publisher: | CSIR |
Abstract: | The ethyl-5-[3-(ethoxycarbonyl)-4-hydroxybenzyl]- 2-hydroxybenzoate 3 is prepared by the usual esterification of 5-(3-carboxy-4-hydroxybenzyl)-2-hydroxy benzoic acid 2. Compound 3 on reacting with ethyl acetoacetate yields 3-acetyl-6-[(3-acetyl-4-hydroxy-2-oxo-2H-6- chromenyl)methyl]-4-hydroxy-2H-2-chromenone 4. The regioselective conversion, by cyclizing the hydrazone 5 of compound 4 to either 8,8'-methylene-bis-4-oxo-1,4-dihydrochromeno [4,3-c]pyrazoles 6 with p-toluene sulfonic acid in refluxing xylene or 8,8'-methylene-bis-4-oxo-2,4-dihydro chromeno[4,3-c]pyrazoles 7 with corresponding hydrazine hydrochloride in refluxing acetic acid is described. |
Page(s): | 319-324 |
URI: | http://hdl.handle.net/123456789/1419 |
ISSN: | 0376-4699 |
Appears in Collections: | IJC-B Vol.47B(02) [February 2008] |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
IJCB 47B(2) (2008) 319-324.pdf | 127.18 kB | Adobe PDF | View/Open |
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.