Subscribe to RSS
Please copy the URL and add it into your RSS Feed Reader.
https://www.thieme-connect.de/rss/thieme/en/10.1055-s-00000084.xml
Synthesis 1994; 1994(12): 1437-1440
DOI: 10.1055/s-1994-25709
DOI: 10.1055/s-1994-25709
paper
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.
Synthesis of 3-Substituted-7-alkoxy-5H-pyrazolo[4,3-d]-1,2,3- triazin-4-(3H)-ones
Further Information
Publication History
Publication Date:
25 April 2002 (online)
An efficient method for the preparation of 3-substituted-7-alkoxy-5H- pyrazolo[4,3-d]-1,2,3-triazin-4(3H)-ones 7a-n is described. Isopropyl 1,4-dinitropyrazole-5-carboxylate (2) underwent aromatic nucleophilic "cine" substitution with concomitant ester hydrolysis to give 3(5)-alkoxy-4-nitropyrazole-5(3)-carboxylic acids 3a-c, when it was reacted with an alcoholic solution of potassium hydroxide at room temperature. The latter were converted into the final compounds 7a-n through a four step sequence, involving: i) carboxylic acid activation, ii) carboxamide formation, iii) nitro group reduction, and iv) intramolecular diazotization.