Heterocyclization of Functionalized Heterocumulenes with C,N‐ and C,O‐Binucleophiles. Part 1. Cyclocondensation of 1‐Chloroalkylheterocumulenes and N‐(1‐Chloroalkylidene)urethanes with 2‐Cyanomethylpyridine.

Abstract

The reaction of 2-cyanomethylpyridine (I) with 1-chloroalkyl isocyanates (II), 1-chloroalkylcarbodiimides (V), 1,1-dichloroalkyl isocyanates (VII) as well as N-(1-chloroethylidene)-O-methylurethanes such as (IX) results in the formation of cyclization products having a pyrido[1,2-c]pyrimidine structure. -(VOVK, M. V.; LEBED, P. S.; CHERNEGA, A. N.; PIROZHENKO, V. V.; BOIKO, V. I.; TSYMBAL, I. F.; Chem.

Heterocyclization of functionalized heterocumulenes with C,N- and C,O-binucleophiles: IV. Reactions of 1-chloroalkylheterocumulenes and N-(1-chloroalkylidene)carbamates with 2-benzimidazolylacetonitriles and methyl 2-benzimidazolylacetates

“…Basing on the previously found [2,3] effect of reaction conditions of the 1-chloroalkyl isocyanates with the derivatives of 2-pyridyl-and 2-benzothiazolylacetic acids on the structure of the cyclocondensation products we presumed that the revealed relations would hold also for the 2-benzimidazolyl acid derivatives.…”

“…This downfield signal is due to the deshielding effect of the C=O group [2,3]. In addition in the 13 C NMR spectrum of compound IIIb the signal from carbon atom of the C=O group is located at 146.93 ppm; in the spectrum of an 3-oxo isomer this signal should have appeared in the range 160166 ppm [2,3]. Compounds IIIgi were not isolated in the analytically pure state.…”

“…In particular, 1 H NMR spectra contain the doublet of proton H 9 at 8.46 8.63 ppm in keeping with the spectral data of the structural analogs [2,3,7].…”

“…The assumed structure was reliably identified by the presence of the most downfield signal among those from the aromatic protons belonging to the H 9 doublet in the range 7.837.97 ppm. This downfield signal is due to the deshielding effect of the C=O group [2,3]. In addition in the 13 C NMR spectrum of compound IIIb the signal from carbon atom of the C=O group is located at 146.93 ppm; in the spectrum of an 3-oxo isomer this signal should have appeared in the range 160166 ppm [2,3].…”

“…We formerly [2,3] reported on a regioselective cyclization of 1-chloroalkylheterocumulenes and N-(1-chloroalkylidene)carbamates with derivatives of 2-pyridyland 2-benzothiazolylacetic acids that provided a new synthetic approach to trihalomethyl-containing 1H-pyrido- [1,2-c]pyrimidines and pyrimido [6,1-b] [1,3]benzothiazoles. In this study aiming at preparation of virtually unknown [4] trihalomethyl-substituted benzimidazo [1,2-c]pyrimidines we investigated reactions of a series of trihalomethylsubstituted 1-chloroalkylheterocumulenes and their derivatives with 2-benzimidazolylacetonitriles and methyl 2-benzimidazolylacetates.…”