Synthesis and crystal structure of some 3,5-pyrazolidinediones

“…In addition, comparing analytical data of the isolated malonohydrazide ( 4 ) with that of authentic sample of malonohydrazide (m.p. 151–153 °C) [ 40 ] revealed them to be identical in all aspects. Moreover, the proposed mechanism proved the needed molar ratio of hydrazine hydrate (2.5 mol equiv.)…”

Section: Resultsmentioning

confidence: 99%

“…Ethyl 3-hydrazinyl-3-oxopropanoate ( 7 ) was prepared according to the reported method (m.p. 68–69 °C) [ 40 ].…”

Section: Methodsmentioning

confidence: 99%

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

et al. 2013

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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.

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“…Pyranopyrazoles [9], 1,3-thiazines [10], thiazoles [11], thienopyrazoles [12], and furopyrazole [13] represent important classes of heterocycles, which have been developed for different purposes in the pharmaceutical field. In continuation of our previous works, which had dealt with using active nitriles in synthesis of polyfused-and spiropyrazoles [14][15][16][17][18][19][20][21], herein, we report the synthesis of pyrano[2,3-c] pyrazole, thiazole, 1,3-thiazine, 1,3-oxothiinopyrazole, and furo[2,3-c]pyrazole derivatives starting with 1phenylpyrazolidine-3,5-dione [1][2][3][4]10,14].…”

Section: Introductionmentioning

confidence: 99%