α-Diaminoboryl carbanions, readily prepared from acetonitrile, stereoselectively convert 2-nitrobenzaldehydes into nitrophenyl (Z)-acrylonitriles. Subsequent reductive cyclization leads to a series of 2-aminoquinoline derivatives. The entire procedure is practically operated in a single flask.

Efficient syntheses are described for the synthetically important 3-methylquinoline-4-carbaldehydes 6a-h from o-nitrobenzaldehydes 1a-h employing a Wittig-olefination-Claisen-rearrangement protocol. The Wittig reaction of o-nitrobenzaldehydes with crotyloxymethylene triphenylphosphorane afforded crotyl vinyl ethers 2a-h, which on heating under reflux in xylene underwent Claisen rearrangement to...

Baylis-Hillman reactions of 2-nitrobenzaldehydes with various activated alkenes afford adducts that undergo reductive cyclisation to quinoline derivatives. The chemo- and regioselectivity of cyclisation appears to be influenced by the choice of both the substrate and the reagent system, and competing reactions have been observed.

Methods for the construction of thiazolo-, thiazino-, and thiazepino-2H-indazoles from o-nitrobenzaldehydes or o-nitrobenzyl bromides and S-trityl-protected 1°-aminothioalkanes are reported. The process consists of formation of the requisite N-(2-nitrobenzyl)(tritylthio)alkylamine, subsequent deprotection of the trityl moiety with TFA, and immediate treatment with aq. KOH in methanol under Davi...

Combined experimental and theoretical studies on molecular and vibrational structure of 2-nitrobenzaldehyde and 4-nitrobenzaldehydes are reported. The Fourier transform infrared and Fourier transform Raman spectra of 2NB and 4NB has been recorded in the solid phase. The optimized geometry has been calculated by HF and B3LYP methods with 6-311++G(d,p) basis set. The harmonic vibrational frequenc...