The Reaction of Ethyl 2-oxo-2H-chromene-3-carboxylate with Hydrazine Hydrate

Molecules

Hatem A. Abdel-Aziz¹  Tilal Elsaman¹  Mohamed I. Attia¹ 

[1] ¹Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia ²Department of Applied Organic Chemistry, National Research Center, Dokki, Cairo 12622, Egypt ³Department of Medicinal and Pharmaceutical Chemistry, National Research Center, Dokki, Cairo 12622, Egypt

关键词: salicylaldehyde azine;    malonohydrazide;    coumarins;    hydrazides/hydrazones;    ring-opening;   

DOI  :  10.3390/molecules18022084

来源: mdpi

【 摘 要 】

Although salicylaldehyde azine (3) was reported in 1985 as the single product of the reaction of ethyl 2-oxo-2H-chromene-3-carboxylate (1) with hydrazine hydrate, we identified another main reaction product, besides 3, which was identified asmalono-hydrazide (4). In the last two decades, however, some articles have claimed that this reaction afforded exclusively hydrazide 2 and they have reported the use of this hydrazide 2 as a precursor in the syntheses of several heterocyclic compounds and hydrazones 6. We reported herein a study of the formation of 2 and a facile route for the synthesis of the target compounds N'-arylidene-2-oxo-2H-chromene-3-carbohydrazides 6a–f.

【 授权许可】

CC BY   
This is an open access article distributed under the Creative Commons Attribution License (CC BY) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.