The formation of derivatives of dihydro‐benzimidazole and tetrahydroquinoxaline by the action of acetic anhydride and zinc chloride on nitro‐derivatives of alkylanilines

Abstract

The introduction of an acetyl group into the benzene n'ucleus of atniline by heating the latter with acetic anhydride and zinc chloride takes place v e q e d y . With mano-and b a t h y l n i b , howleyer, the method is not a success.Some years ago, while working in this laboratory, Mr. Hoejenbos, chem. docts., treated 3 : 6-dinitrodiethylaniline, mp. 7 6 O , in the same mamar, and alrtaimdi a beautifully a r y s t a b p&ct (ntp. 1 2 7 O ) , with the study of which, however, he could, not pmceed.Some time ago we agoin took up the investigation of this substance and at the same time studied the action of acetic anhydride and zinc chloride on other nitro-derivatives of didkyladlines.It was found, that not only the nitro-compound, mentioned above, but also 2 : 4-dinitrodiethylaniline, as well as 3 : 6and 2 : 4-dinitroand 3 : 4 : 6-t~iniltro-dim~ebhylaniline gave easily crystallisabk reaction products.The analyses of all these compounds, which were obtained as principal products in the reaction, indicated that only one acetyl group had been introduced into the molecule, and that at the same time one mol of waiter had been: removed.We thought at first that @he entering acetyl group had replaced one atom of hydrogen in the benzene nucleus, but we had to give up this opinion, because a prolonged investigation proved that this acetyl group could easily be diminated by heating with 10 $% caustic potash solution, and could (easily be reintroduced into some of the compounds, which rn bnrger containled an aueityl! group. Tb d m of potash did not produce amines, as i s the case with the unsubstituted nitro-products.The analyses of the deacetylated c o m p o d s pointed to substances, which had been formed from the original substance by the removal of the elemmnibs of a m mol. of water.'The question to be solved was: what groups in the molecule had taken p r t in rhe fiormation of water. It was obvious to assume that

Study on the host–guest complex of dicyclohexanocucurbit[6]uril and 2-phenylbenzimidazole, and its recognition effect toward Fe 3+

“…Benzimidazole compounds [1][2][3][4][5] are aromatic heterocyclic compounds containing two nitrogen atoms. Benzimidazole derivatives and metal complexes exhibit good biological activity.…”