R. N. Nesterenko

Pyrroles from ketoximes and acetylene

Abstract2-(2-Furyl)pyrroles and 1-vinyl-2-(2-furyl)pyrroles were obtained in up to 80% yields in the reaction of ketoximes of the furan series with acetylene in MOH—dimethyl sulfoxide (M = Li, K) Superbase media.

ADDITION OF METHYL MERCAPTOACETATE TO N-VINYLPYRROLES

Methyl esters of 2-(pyrryl-1)ethylthioacetic acid were synthesized in 53–71% yield by addition of methyl mercaptoacetate to N-vinylpyrroles. Their reactions with ammonia and hydrazine hydrate were investigated.

Synthesis of 2-(2-selenienyl)pyrrole from methyl-2-selenienylketoxime and acetylene

The reaction of methyl-2-selenienylketoxime with acetylene in KOH-DMSO gives 2-(2-selenienyl)pyrrole and its 1-vinyl derivative.

Stereochemical aspects of pyrrole formation from substituted piperidin-4-one oximes and acetylene

Oxime derivatives of 1,2,5-trimethylpiperidin-4-one, 2-methyl-, and 2-(2-furyl)-4-ketodecahydroquinoline react with acetylene to form substituted pyrrolo[3,2-c]piperidines and their N-vinyl derivatives. During the course of pyrrolization the configuration at the 7-position is partially changed, resulting in the formation of two stereoisomeric pyrroles.

Pyrroles from ketoximes and acetylene. No. 36. 4,4,6,6-Tetramethyl-4,5,6,7-tetrahydro-5-azaindole, its nitroxyl and vinyl derivatives, and spin-labelled copolymer

An oxime containing a nitroxyl functional group site, 2,2,6,6-tetramethyl-1-nitroxyl-4-hydroxyiminopiperidine, has been shown for the first time to engage in productive pyrrole synthesis via reaction with acetylene in KOH-DMSO. The behavior of 2,2,6,6-tetramethyl-4-piperidone oxime and its 1-hydroxy derivative in this reaction has also been investigated. The corresponding 5-azaindole and its 5-nitroxyl and 1-vinyl derivatives have been synthesized in this manner. 1-Hydroxy-4-piperidone oxime reacts at 50–60‡C under the general reaction conditions undergoing oxidative conversion to 5-azaindole, while at 105‡C in the presence of excess acetylene reduction of the hydroxy group also takes place. The formation of a pyrrole ring does not involve radical chains, although vinylation of the resulting pyrroles apparently involves one-electron transfer. 1-Vinyl-4,4,6,6-tetramethyl-4,5,6,7-tetrahydro-5-azaindole has been used for the preparation of a spin-labelled polyvinyl alcohol copolymer.

ALKENYLATION BY 5-HEXEN-2-ONE OXIME: PROTOTROPIC ISOMERIZATION UNDER TROFIMOV REACTION CONDITIONS

From 5-hexene-2-one oxime (I) and acetylene in KOH/DMSO, 2-methyl-3-(2-propenyl)pyrrole (II), E- and Z-2-methyl-3-(1-propenyl)pyrroles (III), and E- and Z-1-vinyl-2-methyl-3-(1-propenyl)pyrroles (V) were synthesized. The isomerization of the alkenyl radical of pyrroles II was studied.

Pyrroles from ketoximes and acetylene. 41. Some reactions of 1-vinyl-2-(2-furyl)- and-(2-thienyl)pyrroles

We have studied the reaction of 1-vinyl-2-(2-furyl)- and -(2-thienyl)pyrroles with trifluoroacetic anhydride, with hydrogen in the presence of catalysts (Raney nickel, palladium black, palladous chloride), with propargyl alcohol in electrophilic conditions [catalysis by perfluorobutyric acid in the system azoisobutyrodinitrile (AIBN)-CCl4), and with alkane thiols with AIBN initiation. The products are novel substituted hetarylpyrroles.

Pyrroles from ketoximes and acetylene. 40. Reaction of alkyl hetaryl ketoximes with 1,2-dichloroethane in superbase media

Abstract2-(2-Furyl)- and 2-(2-thienyl)pyrroles and their N-vinyl derivatives were synthesized by the reaction of alkyl furyl (thienyl) ketoximes with 1,2-dichloroethane in superbase media. 2-Chloroethyl and vinyl ethers of alkyl hetaryl ketoximes are intermediates in the reaction.

New examples of the vinylation of NH-heterocycles with acetylene at atmospheric pressure in the KOH-DMSO system

Vinylation of 2-hetarylpyrroles, 4,5-dihydrobenzo[g]indole, and 1,2,3,4-tetrahydro-γ-carbinols at atmospheric pressure in the superbasic system KOH-DMSO at 100–120 ° C has given the corresponding N-vinyl derivatives in yields of 92–99%.