Thermolysis of symmetrical dithiobiurea and thioureidoethylthiourea derivatives

Abstract

Microwave and thermal heterocyclization of N,N -disubstituted hydrazinecarbothioamide 1a,b and substituted thioureidoethylthioureas 2a-c as well as 1-phenyl-3[2-(3-phenylthio-ureido)phenyl]-thiourea 6 are reported. C

Microwave irradiation assisted facile synthesis of new imidazole, pyrazine, and benzodiazocine derivatives using diaminomaleonitrile

“…To the best of our knowledge, synthesis of heterocyclic compounds by the reaction of diaminomaleonitrile (DAMN) with either acid chloride derivatives, diketones, or dialdehydes have not yet been investigated. As an extension to our work concerning the synthesis of heterocyclic compounds using facile simple methods [2], we investigated the use of microwaves as an energy source in the synthesis of different heteroaromatic compounds. Diaminomaleonitrile (DAMN) serves as a convenient base model for the synthesis of a large number of novel het-erocyclic compounds [3][4][5][6][7][8][9].…”

Synthesis and Antimicrobial Evaluation of Some New 1,2-Bis-(2-(<i>N</i>-arylimino)-1,3-thiazolidin-3-yl)ethane Derivatives

“…41) Reaction of N,N′-dibenzylethylene-bis-thiourea 8 with 2 eq of the hydrazonoyl chlorides 2a-c under the same reaction conditions as above afforded the corresponding 1,2-bis-(5-arylazo-2-(Nbenzylimino)-4-methyl-1,3-thiazolidin-3-yl) ethane derivatives 11a-c as shown in Chart 2 via a mechanism similar to that in Chart 1. Elemental analysis and spectral data of the reaction product were in agreement with the assigned structures.…”

Reaction of 4‐substituted thiosemicarbazides with (2,4,7‐trinitro‐9H‐fluoren‐9‐ylidene)propanedinitrile

“…Since N 2 of the thiosemicarbazide group is a softer nucleophilic center than the harder and more powerful terminal nitrogen N 1 , reagents susceptible to nucleophilic attack by N 1 may in a second step undergo cyclization to afford the aforesaid heterocycles in excellent yields, even under mild reaction conditions [8,9,15]. It had been reported earlier that (2,4,7-trinitro-9H-fluoren-9-ylidene)propanedinitrile (2) and other 9-(dicyanomethylene)nitrofluorene derivatives react with secondary amines with subsequent substitution of cyano by amino groups to afford trinitro-substituted-9-(aminomethylene)-fluorenes [26], while we have reported the complex reaction of N-arylisoindolines (being tertiary amines) with 2 [27].…”

“…Four-, five-, six-and seven-membered heterocyclic compounds were prepared by reaction of thiosemicarbazide derivatives with a-and -haloketones [11][12][13][14]. In addition, microwave (MW) heating of thiosemicarbazides has been employed for rapid synthesis of a wide variety of heterocyclic compounds such as thiadiazole, triazole-3-thiol, thioxoimidazole and thiadiazepine derivatives [15,16]. Also, the thermal cyclization of 1-aryl/alkyl-2-alkylisothiobiureas afforded 1,2,4-triazolines [17].…”