A simple and efficient synthesis of novel naphthyridine-1-H-pyrazole-4-carboxylic acid esters/carbaldehydes using Vilsmeier-Haack reagent

Heterocyclic communications

article

Muggu V.S.R.K. Chaitanya¹  Pramod K. Dubey¹ 

[1] Department of Chemistry, Jawaharlal Nehru Technological University, Hyderabad College of Engineering

关键词: (diacetoxyiodo)benzene;    hydrazide;    β-keto esters;    naphthyridine;    substituted acetophenone;    Vilsmeier-Haack reagent;   

DOI  :  10.1515/hc-2012-0097

学科分类：内科医学

来源: De Gruyter

【 摘 要 】

The reaction of hydrazide 4 with β-keto esters 5 gave hydrazones 6 . Cyclization of 6 with Vilsmeier-Haack reagent (DMF-POCl 3 ) for 20 min at room temperature gave 1-(4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carbonyl)-1 H -pyrazole-4-carboxylic acid ethyl esters 7 . The treatment of 4 with substituted acetophenones 8 yielded the corresponding hydrazones 9 of substituted acetophenones. The treatment of 9 with Vilsmeier-Haack reagent (DMF-POCl 3 ) for 30 min at room temperature gave product 10 , the reaction of which with (diacetoxyiodo)benzene in ethanol at room temperature for 12 h in the presence of molecular iodine furnished 7 .

【 授权许可】

CC BY|CC BY-NC-ND