Polyfunctional pyrazoles. 7*. Ethyl 1-aryl-4-formylpyrazole-3-carboxylates in the synthesis of 2-aryl-2,4-dihydro-6H-thieno-[3,4-c]pyrazol-6-ones

Polyfunctional Pyrazoles. 9*. Synthesis of 1-Alkyl(Aryl)-3-[4-(Hydroxymethyl)-1Н-Pyrazol-3-Yl]UReas

“…Melting points were determined on a Kofler hot bench and were not corrected. Compounds 1а-d were synthesized according to a published method [11]. Compound 1а.…”

“…Due to this reason, to achieve our goals we explored an effective synthetic route that relied on simple transformations of previously described [11] ethyl 4-hydroxymethylpyrazole-3-carboxylates 1a-d. Hydrazinolysis of these starting materials in refluxing ethanol gave the hydrazides 2a-d, the interaction of which with sodium nitrite in a mixture of hydrochloric and acetic acids led to the pyrazoyl azides 3a-d, compounds that are stable at room temperature. According to 1 Н NMR data, the obtained samples had an assay of 90-93%, and were used in further transformations without additional purification.…”

Polyfunctional Pyrazoles. 10*. Synthesis of 5-OXO-4,5,7,9-Tetrahydropyrazolo[3,4-е][1,2,3]-Triazolo[1,5-а][1,3]Diazepine-3-Carboxamides in a Tandem Reaction of Ethyl 4-(Azido-Methyl)Pyrazole-3-Carboxylates with Cyanoacetamides

“…Among the azidobenzoate pyrazole analogs such transformations are described only for ethyl 5-azido-1-methyl-4-pyrazolecarboxylate, reaction of which with activated nitriles gave 3-substituted pyrazolo[4,3-e][1,2,3]triazolo[1,5-a]pyrimidines [10]. To us it seemed worthwhile to exploit the synthetic potential of tandem reactions of other pyrazole functional derivatives with cyanoacetic acid amides to obtain new condensed heterocyclic compounds.In this work, 4-(azidomethyl)pyrazole-3-carboxylic acid esters 2a-c, formed in essentially quantitative yields by reacting 4-chloromethylpyrazole-3-carboxylic acid ethyl ester 1a-c [11] with sodium azide in DMF solution at 50°C, were studied as potential substrates for tandem condensation reactions. A characteristic of…”

“…In this work, 4-(azidomethyl)pyrazole-3-carboxylic acid esters 2a-c, formed in essentially quantitative yields by reacting 4-chloromethylpyrazole-3-carboxylic acid ethyl ester 1a-c [11] with sodium azide in DMF solution at 50°C, were studied as potential substrates for tandem condensation reactions. A characteristic of…”

“…In this work, 4-(azidomethyl)pyrazole-3-carboxylic acid esters 2a-c, formed in essentially quantitative yields by reacting 4-chloromethylpyrazole-3-carboxylic acid ethyl ester 1a-c [11] with sodium azide in DMF solution at 50°C, were studied as potential substrates for tandem condensation reactions. A characteristic of compounds 2a-c is the location of the azide group in the γ-position relative to the ester group, which is an important prerequisite for the formation of a seven-membered heterocyclic system.…”