3815-86-9Relevant academic research and scientific papers
The reaction of ethyl 2-oxo-2H-chromene-3-carboxylate with hydrazine hydrate
Abdel-Aziz, Hatem A.,Elsaman, Tilal,Attia, Mohamed I.,Alanazi, Amer M.
, p. 2084 - 2095 (2013/04/23)
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 as malono-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.
Synthesis and crystal structure of some 3,5-pyrazolidinediones
Metwally, Saoud A.M.,Moneim, Maisa I. Abdel,Elossely, Yasser A.,Awad, Radwa I.,Abou-Hadeed, Khaled
, p. 426 - 437 (2014/05/06)
Syntheses of various derivatives of 3,5-pyrazolidenedione are reported. This includes 4-arylidene (alkylidene or aralkylidene)-3,5-pyrazolidinediones, which on epoxidation gave unreported oxiranes. The syntheses of these derivatives were based on either the Knoevenagel reaction of carbonyl derivatives with 3,4-pyrazolidinedione or cyclization of arylidene (alkylidene) malonic acid hydrazide with glacial acetic acid. 4-Arylazo-3,5-pyrazolidinedione derivatives were also prepared by coupling of aryldiazonium salts with 3,5-pyrazolidinedione or cyclization of arylazomalonic acid hydrazide. Reduction of 4-benzylidene derivatives gave the corresponding benzyl derivatives. The structure of the new products was confirmed by elemental and spectral analyses and X-ray crystallography.
Efficient synthesis of 4-ethoxycarbonyl pyrazolin-5-one derivatives
Jung, Jae C.,Watkins, E Blake,Avery, Mitchell A.
, p. 3767 - 3777 (2007/10/03)
Concise and efficient methods for the preparation of 3-substituted 4-ethoxycarbonylpyrazolin-5-ones are described. The synthetic strategies involve carbon-acylation in the presence of base, followed by ring cyclization with hydrazine or hydrazine monohydrochloride.
Synthesis of 3-substituted and 3,4-disubstituted pyrazolin-5-ones
Jung, Jae-Chul,Watkins, E.Blake,Avery, Mitchell A
, p. 3639 - 3646 (2007/10/03)
The synthesis of 3-substituted and 3,4-disubstituted pyrazolin-5-ones from acylated ethyl acetoacetates and diethyl malonates is described. The reaction of acylated ethyl acetoacetates and diethyl acetylmalonate with hydrazine (98%) gave 3-substituted pyrazolin-5-ones and malonyldihydrazide, respectively, following a deacetylation-condensation sequence. The reaction of ethyl 2-acetyl-3-hydroxy-2-butenoate and diethyl 2-(1-hydroxyethylidene)malonate with hydrazine monohydrochloride yielded ethyl 3,5-dimethyl-1H-pyrazole-4-carboxylate and 4-ethoxycarbonyl-3-methylpyrazolin-5-one, respectively, following a dehydration-cyclocondensation sequence, in high yields.
