1,2-disubstituted benzimidazoles

2-alkylthiobenzimidazoles [1a-f] were prepared and reacted with epichlorohydrin in absolute ethanol and in presence of alkalis. In the former case, epoxides [2a-f] were produced, while in the latter propanediol derivatives [3a-d] were obtained. Reaction of 2- isoamylthiobenzimidazoles with epichlorohydrin in either absolute ethanol or aqueous alkalis afforded the corresponding epoxides [2e and 2f, respectively]. Structures of the final products were confirmed by spectroscopic and chemical methods

Chemical study of the alkylation of benzimidazole-2thiol and benzothiazole-2thiol with epichlorohydrin

Three isomeric products [3a and 4b] were obtained from the alkylation of [1] with epichlorohydrin under different reaction conditions. The epoxide [3a] was found to be convertible to [4a], while [4a] and [4b] were nonconvertible to each other and proved to be stereo- isomers. Mechanisms of formation of these isomers were attempted. Alkylation of [2] with epichlorohydrin was epichlorohydrin was also investigated and shown to produce [10] or [11]. Structures of the final products were evidenced by spectroscopic data and variable routes of synthesis

Synthesis of 2-amino-2-thiazoline derivatives structurally related to antihistaminic agents

2-amino-2-thiazoline [1] was prepared and was allowed to react with chloroacetyl chloride to give the 2-chloroacetylimino-thiazolidine [IIa]. The latter reacted with certain amines to afford the corresponding 2-substituted-acetylimino-thiazolidines [IIb- m]. Reaction of [IIa] with KI yielded the 2-iodoacetylimino-2- iodoacetylimino-2-thiazolidine [IIn]. Structure of the newly synthesized compounds was confirmed by spectroscopic methods. Attempts to cyclize [IIa] or [IIn] through dehydrohalogenation were not fruitful

Synthesis and cyclocondensation of 2-arylidene-aminothiazolines with chloroacetyl chloride and mercaptoacetic acid

2-aminothiazoline was prepared and allowed to condense with certain aromatic aldehydes affording 2-arylidene-aminothiazolines [1]. Cyclocondensation of the latter with chloroacetyl chloride and mercaptoacetic acid yielded the corresponding thiazolinylthiazolidin- 4-ones [III], respectively. Structure of the new compounds was confirmed by spectroscopic methods

Synthesis and structure elucidation of benzothiazole containing compounds for antimicrobial investigation

Attempted cyclo-addition of benzimidazole-2-thiol with arylidenemalononitriles [1] was unsuccessful. 2-cyanomethyl-1,3- benzothiazole [6] condensed with certain aromatic aldehydes to produce [7], cyclo-addition of which with cyanoacethydrazide [3] yielded [8]. Structure of the newly synthesized compounds was substantiated by spectroscopic data and/or unambiguous synthesis. Representative compounds were screened for antimicrobial activity

Synthesis and reactions of certain-substituted cyclohexanones

Arylidene-alpha-acetothienones [I] reacted with ethyl acetoacetate and acetylacetone to yield thienyl-substituted cyclohexenone derivatives [II]. Mannich reaction of [IIa] and [IIe] with formaldehyde and piperidine gave the desired products [III], while [IIa] reacted slowly with hydrazine hydrate to yield the hydrazide [IV]. Additionally, the deethoxycarbonylation production [V] obtained by treatment of [IIe] with alcoholic sodium hydroxide, reacted smoothly with hydrazine hydrate, phenylhydrazine, hydroxylamine and a number of secondary amines under the Mannich conditions to furnish the corresponding derivatives [VI], [VII] and [VIII] respectively

Reaction of arylidene-a-acetothienones with nitroalkanes

Michael type condensation of [I] with nitroalkanes has been affected. The reaction with nitromethane produced a bis adduct [III] instead of the expected product [II]. However, piperidine catalyzed condensation of [I] with nitroethane and 2-nitropropane afforded a good yield of the normal adducts [IV] and [V] respectively

Synthesis and cyclocondensation reactions of 4 [5] imidazolylmethylaminochalcones

4 [5]-chloromethylimidazole [1] condensed with p-aminocetophenone to give [II]. The reaction of the latter with aromatic aldehydes produced the corresponding chalcone derivatives [III], which underwent cyclocondensation reactions with hydroxylamine hydrochloride, hydrazines, urea and thiourea to afford isoxazolines [IV], pyrazolines [V], 5,6-dihydropyrimidin-2 [IH]-one [VI] and 5,6-dihydropyrimidin-2 [IH]-thione [VII], respectively. Some of the new compounds were tested for their antihistaminic activity