ChemInform Abstract: ALKYLATION OF SOME CYANO DERIVATIVES OF BENZIMIDAZOLES

Abstract

Die Alkylierung der Benzimidazole (I) mit Benzylchlorid (Va) liefert die Seitenketten‐Substitutionsprodukte (II); die Alkylierung des Benzimidazols (III) ‐ als Tautomerengemisch mit der Form (IV) vorliegend ‐ mit den Reagenzien (V) bzw. (VI) gibt dagegen die Derivate (VIIa) [mit l mol (Va)] bzw. (VIIb) [mit 2 mol (Va)], (VIIc) bzw. (VIId).

Detailed Studies of the Alkylation Sides of Pyridin‐2‐yl and 4,6‐Dimethylpyrimidin‐2‐yl‐cyanamides

“…Second, the IR spectra showed that cyano group is represented by an absorption band at 2225–2240 cm −1 , which is in excellent agreement with the structure ―N(R)―C≡N. The alkylation of endo‐cyclic nitrogen atom should lead to the formation of cyanoimino =N―C≡N group, in which an absorption band of cyano group is given at 2150–2190 cm −1 .…”

“…For cyanamide 1 , isomer Ib is more energetically preferable, but the difference in the energies of isomers Ia and Ib is small. For cyanamide 2 , the isomers IIa and IIc are energetically favorable, and the formation of alkylated carbodiimide derivatives Ic and IIc has not been reported for the studied reaction . Thus, we can predict that the reaction with 1 in thermodynamic conditions can produce both Ia and Ib , with Ib being slightly more favorable, while the only product of reaction with 2 will be IIa .…”

“…Triazinylcyanamides were reported to react with a wide range of haloalkanes and halocarboxylic acid derivatives . Also, a series of N ‐alkyl 2‐cyanoaminobenzimidazole derivatives were obtained . Stanovnik and co‐workers pioneered the methylation of cyanoamino‐pyridazines and ‐pyrazines by using dimethylformamide‐dimethylacetal (DMFDMA) and diazomethane , respectively.…”

“…As we were well aware, the alkylation of triazinylcyanamides and cyanoaminopyridazines was carried out at cyanoamino group, but in other cases the reaction proceeded with participation of the heterocyclic moiety. For example, 2‐cyanoaminobenzimidazole was alkylated at the two nitrogen atoms of benzimidazole ring . In the case of cyanoaminopyrazines, the alkylation proceeded with the formation of approximately equal amount of N ‐alkyl‐ N ‐(pyrazin‐2‐yl)cyanamides and N‐1 alkylated pyrazines .…”

Research in the field of imidazo[1,2-a]benzimidazole derivatives: XXVII. 1-acylmethyl-2-(ω-hydroxyalkylamino)-benzimidazoles and their transformation into derivatives of tricyclic systems

“…Unlike the 2-aminobenzimidazole that in the reaction with acylmethylbromides [11,12] and with esters of haloacetic acids [13] even in a neutral medium and under mild conditions (acetone, room temperature [12]) formed mixtures of N-acyl-(alkoxycarbonyl)methyl-substituted and of the corresponding N,N'-disubstituted 2-aminobenzimidazoles, the alkylation of 2-hydroxyalkylaminobenzimidazoles Ia and Ib, with haloketones IIb-IIe proceeded under more stringent conditions and resulted only in monosubstituted III and IV.…”