Synthesis of new iminocoumarins and their transformations into N-chloro and hydrazono compounds

The synthesis and optical properties of novel fluorescent iminocoumarins and bis-iminocoumarins: Investigations in the series of urea derivatives

Synthesis of substituted 3‐(5‐amino‐[1,3,4]thiadiazol‐2‐yl)‐2H‐pyrano[2,3‐c]pyridin‐2‐ones

Synthesis of 2‐Amino‐3‐cyano‐4H‐chromene‐4‐carboxamide Derivatives by an Isocyanide‐Based Domino Conjugate Addition/O‐Trapping Rearrangement Sequence

This chapter surveys the literature published from 1996 onward on cyclically conjugated compounds: 1,3,4-oxadiazole 1,3,4-oxadiazolinones, 1,3,4-oxadiazolinethiones, and 1,3,4-oxadiazolinimines, as well as their derivatives. Also, reduced systems derived from those systems have been reviewed. The compounds have been characterized by the results of theoretical calculations and experimental structural methods. The reactivity of the ring atoms in fully conjugated compounds and substituents attached to the ring carbon or nitrogen atoms have been discussed. The ring syntheses from acyclic precursors or by transformations of other heterocycle have been compared. It has been documented that 1,3,4-oxadiazole ring is present in several biologically active compounds and in nonpolymeric or polymeric electron-transporting dyes. It also has been shown that oxadiazole derivatives can serve as potentially useful laser dyes, optical brighteners, scintillators, or electrophotographic photoconductors. This chapter contains over one hundred references to original papers.

1,3,4-Oxadiazoles

A new method for the synthesis of 3-(1,3,4-oxadiazol-2-yl)coumarins is proposed. It is based on the recyclization of 2-(N-aroylhydrazono)coumarin-3-carboxamides, which are readily obtained by the reaction of 2-iminocoumarin-3-carboxamides with arenecarboxylic hydrazides in an acidic medium. Advantages of the given method over alternative synthetic schemes were shown. Proposals on the mechanism of reaction were made.

Recyclization of 2-imino-2H-1-benzopyrans by the action of nucleophilic reagents 4. Use of 2-(N-aroylhydrazono)coumarin-3-carboxamides for the synthesis of 3-(1,3,4-oxadiazol-2-yl)coumarins

Recyclization of 2-Imino-2H-1-benzopyrans by the Action of Nucleophilic Reagents. Part 4. Use of 2-(N-Aroylhydrazono)coumarin-3-carboxamides for the Synthesis of 3-(1,3,4-Oxadiazol-2-yl)coumarins

V. M. Nikitchenko

Papers

Recyclization of 2-imino-2H-1-benzopyrans by the action of nucleophilic reagents 4. Use of 2-(N-aroylhydrazono)coumarin-3-carboxamides for the synthesis of 3-(1,3,4-oxadiazol-2-yl)coumarins

Recyclization of 2-Imino-2H-1-benzopyrans by the Action of Nucleophilic Reagents. Part 4. Use of 2-(N-Aroylhydrazono)coumarin-3-carboxamides for the Synthesis of 3-(1,3,4-Oxadiazol-2-yl)coumarins