Aqueous hydrolysis of 3-[2-(3-methyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-1-yl)-ethylamino]-and 3-[2-(5-methyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-1-yl)ethylamino]-propanoates

Noncatalytic hydrolysis of methyl 3-[2-(3-methyl-1H-pyrazol-1-y)ethylamino]-and methyl 3-[2-(5-methyl-1H-pyrazol-1-yl)ethylamino]propanoates at 200°C was performed. According to X-ray diffraction data, the resulting acids exist exclusively as salts.     

Synthesis and structure of 1-(buta-1,3-dien-2-yl)pyrazoles and their behavior in Diels-Alder reactions

A convenient procedure has been developed for the synthesis of cis-and trans-isomeric 1-(buta-1,3-dien-1-yl)-1H-pyrazoles by reaction of the corresponding pyrazoles with β-methylacrolein diethyl acetal and subsequent 1,4-cleavage of the nucleophilic substitution products. The behavior of the title compounds in Diels-Alder reactions with maleic anhydride has been studied. According to the ¹H NMR data, 1-(buta-1,3-dien-1-yl)-1H-pyrazole is a mixture of cis and trans isomers. Butadienylpyrazoles having methyl groups in the pyrazole ring do not react with maleic anhydride.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-vinylazoles from vinyl acetate without using mercury catalysts

N-Vinyl-substituted pyrazole, 3(5)-methylpyrazole, imidazole, and 1,2,4-triazole were synthesized by addition of the corresponding azoles to vinyl acetate under conditions of phase-transfer catalysis, followed by pyrolysis of N-(1-acetoxyethyl)azoles thus formed at 350–400°C in the presence of water.     

Synthesis of 4-Vinylmorpholine Based on Acetylene

It has been shown that from the possible methods for the synthesis of 4-vinylmorpholine, the vinylation of morpholine with acetylene remains acceptable. A technologically accessible method for vinylation of morpholine with acetylene at atmospheric pressure was developed.

     

Diels-Alder reactions of 3-and 5-methyl-1-vinylpyrazoles with cyclohexa-1,3-diene and hydrogenation of the reaction products

The behavior of isomeric vinylpyrazoles in the Diels-Alder reactions with cyclohexa-1,3-diene was studied to show that the spatial location of the vinyl group on the N² atom does not affect the diene synthesis.     

13C NMR spectra of 4-hydroxymethylpyrazoles and their chemical behavior at heating

It was established that in the ¹³C NMR spectra of 4-hydroxymethylpyrazoles the carbon atom of hydroxymethyl group of 1,3,5-trimethyl-4-hydroxymethylpyrazole is deshielded by 6.28–6.78 ppm compared to 1-methyl-4-hydroxymethyl-, 1,3-dimethyl-4-hydroxymethyl- and 1,5-dimethyl-4-hydroxymethylpyrazoles. It is assumed that this difference is related to their dissimilar behavior at heating.