E. K. Panisheva

β-(Benzofur-2-yl)-and (indol-2-yl)enamines in the Nenitzescu reaction

Abstract Depending on the volume and electron-withdrawing properties of the substituents in the heterocyclic ring, reaction of β-(benzofur-2-yl)- and -(indol-2-yl)enamines with benzoquinone leads to the formation of 3-heteroarylbenzofurans, with or without a dimethylaminogroup in the position 2. If dehydrogenation is impossible, as in the case of α-methyl-β-heteroarylcnamines, furo[2,3-f]benzofurans are formed.

Investigation by1H NMR of dienediamines as starting materials for the synthesis of indoles and benzofurans by the nenitzescu reaction

Investigations using1H NMR have been carried out on dienediamines which are starting materials for the synthesis of indoles and benzofurans by the Nenitzescu reaction. Protonation of dienediamines and special features of their configuration and conformation were studied.

Acetals of lactams and acid amides. 66. Synthesis and spectral studies of 4(and 6)-amino-5-hydroxyindole derivatives

A method has been developed for the selective N-alkylation of derivatives of 4-amino-5-hydroxy- and 6-amino-5-hydroxyindoles, based on the preliminary closure of the oxazolone ring by reaction with sodium cyanate and alkylation of the resulting oxazolo[4,5-e]- and oxazolo[5,4-f]-indole derivatives in an alkaline medium. The latter, on heating in an alkali, convert into 5-hydroxy-6-methylaminoindoles, while the former give substituted N-methyl-N-indolylurethanes under these conditions. The reaction of amino-hydroxyindoles with DMFA diethylacetal and certain reactions of the resulting amidines were studied.

Reaction of 2-chloro-5-methylbenzoquinone with Β-aminocrotonic ester derivatives

The reaction of 2-chloro-5-methylbenzoquinone with Β-aminocrotonic ester derivatives was studied by PMR spectroscopy in CD3COOD. The spectra indicate the formation of intermediate hydroquinone and quinone derivatives, which subsequently transform into the corresponding indoles. It was shown that the indolization proceeds unequivocally at the 3-position of the initial benzoquinone, and the rate of formation of the indole derivatives decreases with increase in the size of the substituent at the nitrogen atom of the Β-aminocrotonic ester. The starting, intermediate compounds and the end products observed in the PMR spectra were identified by comparison with specially synthesized compounds.