Guanylation of thiosemicarbazones: a new synthetic route to polysubstituted guanylhydrazones with antimicrobial activity

An Update of the Use of Thiocarbohydrazides and Thiosemicarbazides in the Preparation of Heterocycles and Their Biological Importance

“…By both traditional (stirring at r.t) and microwave‐assisted procedures, aryl thiosemicarbazides 53a–d or alkyl thiosemicarbazides 54e–i were obtained from the reaction of alkyl or aryl isothiocyanate 52a – i with hydrazine hydrate or phenyl hydrazine in toluene (Scheme ) .…”

The chemistry and biology of organic guanidine derivatives

“…5 New methods of guanidine synthesis have been reported and are summarized in Table S1 †. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] With regards to yields and ease of preparation, the following methods are of particular interest: the synthesis of triflyl-substituted guanidines from aromatic isothiocyanates, in which the products can be further regiospecifically converted to unsymmetrically tetrasubstituted guanidines; 7 the synthesis of aromatic guanidines from symmetrical carbodiimides using dimethylaluminium chloride as catalyst; 8 a similar approach using samarium iodide; 9 aliphatic amines react with aromatic a-chloroaldoxime methanesulfonates in the presence of tetramethylethylenediamine (TMEDA) to give, after a reaction with either a primary or secondary amine, a tetrasubstituted guanidine via a Tiemann rearrangement; 12 the use of Yb(OTf) 3 as catalyst in the reaction of either primary aromatic or secondary aliphatic amines with carbodiimides give trisubstituted guanidines in good to excellent yields; 14 cycloguanidination of cyanodiaziridinimines on a terminal olefin, in order to obtain imidazolidin-2-imines regiospecifically at a terminal double bond; 15 synthesis of protected tetrahydro-1H-pyrrolo[1,2-c]imidazol-3(2H)-imines and hexahydroimidazo [1,5-a]pyridin-3(5H)imines from the corresponding 1-(2,2-disubstituted-but-3-en-1yl)guanidines and 1-(2,2-disubstituted-pent-4-en-1-yl)guanidines, in the presence of palladium acetate/copper chloride as catalyst; 18 a variety of aromatic and heteroaromatic amines can react with either symmetrical or asymmetrical carbodiimides to provide N,N 0 ,N 00 -trisubstituted guanidines in the presence of AlMe 3 in quantitative yield; 19 a very effective route for the preparation of (E)-benzyl 2-(tosylimino)imidazolidine-1carboxylates by a reaction between a benzyl 2-azidoethylcarbamate and tosylisocyanate, using bis(diphenylphosphino) butane as the azide-reducing agent; 22 guanylation of both primary and secondary amines can be performed with N-iodosuccinimide as the desulfurizating agent, in mo...…”