2-Amino-4-[2-(5-nitro-furyl)vinyl]thiazole and its derivatives

The reactions of 4-bromo-1-(5-nitro-2-furyl)but-1-en-3-one and its 2-methyl and 2-chloro derivatives with thiourea and its N-allyl and N-phenyl derivatives have yielded 2-amino-4-[-5-nitro-2-furyl)-vinyl]thiazole and its - and N-substituted derivatives. 2-Amino-4-[-(5-nitro-2-furyl)vinyl]thiazole and its -methyl derivative have also been prepared by the direct reaction of the corresponding , -unsaturated ketones with bromine and an excess of thiourea in chloroform, as was shown by a comparison of UV spectra. A series of N-acyl derivatives of the aminothiazoles has been obtained. UV and IR spectra are given.     

6-(2-furyl)imidazolo[2, 1-b]thiazole and its derivatives

Imidazolo[2, 1-b]thiazoles have been obtained by cyclizing thiazolium salts synthesized by the reaction of 2-aminothiazole and 2-amino-4-methylthiazole with 2-haloacetylfurans.     

Synthesis and transformations of 2-(2-furyl)- and 2-[β-(2-furyl)vinyl] phenanthr [9,10]imidazoles

The corresponding 2-(2-furyl)- and 2-[-(2-furyl)vinyl] phenanthr[9,10]imidazoles were obtained by the condensation of 9,10 phenanthrenequinone with furfural, -(2-furyl)acrolein, and their 5-bromo and 5-nitro derivatives in the presence of ammonium acetate in glacial acetic acid. Their metallation, acetylation, nitration, and replacement of halogen by a nitro group were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1014–1016, August, 1971.     

Synthesis and transformations of 2-(2-furyl)- and 2-[β-(2-furyl)vinyl]imidazo[4,5-f]quinolines

The corresponding 2-(2-furyl)- and 2-[-(2-furyl)vinyl]imida zo[4,5-f]quinolines were obtained by condensation of 5,6-diaminoquinoline and 5-amino-6-rnethylaminoquinoline with furfural, furylacrolein, and their 5-bromo and 5-nitro derivatives and also with the hydrochlorides of imino esters of furancarboxylic and furylacrylic acids. Alkylation, acetylation, nitration, and substitution of the halogen in the furan ring by a nitro group were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 440–442, April, 1973.     

Synthesis and transformations of 2-(2-furyl)-and 2-[β-(2-furyl)vinyl]imidazo[4,5-b]phenazines

The corresponding 2-(2-furyl)- and 2-[-(2-furyl)vinyl]imidazo[4,5-b]phenazines were obtained by the condensation of 2,3-diaminophenazine with furfural and 2-furylacrolein and with their 5-bromo and 5-nitro derivatives. The phenazines were also synthesized by the reaction of 2-methylimidazo[4,5-b]phenazine with furfural and 5-bromo- and 5-nitrofurfural. The alkylation, acetylation, and nitration of the compounds obtained, as well as replacement of the halogen in the furan ring by a nitro group, were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1425–1428, October, 1971.     

Synthesis and transformations of 2-(2-furyl)-and 2-[β;-(2-furyl)vinyl]naphth[1,2-d]imidazoles

The corresponding 2-(2-furyl)naphth[1,2-d]imidazoles were obtained by heating Schiff bases, prepared from 1,2-naphthalenediamine and furfural and 5-bromo- and 5-nitrofurfurals, in nitrobenzene. 2-[-(2-Furyl)vinyl]naphth[1,2-d]imidazoles were synthesized by condensation of 2-methylnaphth[1,2-d]imidazole with furfural and 5-bromo- and 5-nitrofurfural. The methylation, nitration, and acetylation of the compounds obtained were studied, and the replacement of the bromine atom in the furan ring by a nitro group was also investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1555–1557, November, 1972.     

Mannich bases and methiodides of 6-(2-furyl)imidazo[2,1-b]thiazole and its substituted derivatives

The Mannich reaction in a number of 6-(2-furyl)-substituted imidazo[2,1-b]thiazoles is realized initially in the 5 position of the imidazothiazole system, whereas it is also realized in the 5 position of the furan ring in the presence of excess reagents if the latter position is not substituted. Iodomethylation occurs at the N₇ atom of imidazothiazole. The Mannich bases of 6-(5-nitro-2-furyl)imidazo[2,1-b]thiazole are iodomethylated only at the aminomethyl group. The pK_a values of the series of compounds were measured.     

Synthesis of 2-phenyl-3-(2-furyl) — and 2-phenyl-3-[β-(2-furyl)vinyl]-1,2-dihydro-naphtho[1,2-d]-1,2,4-triazines

The corresponding 2-phenyl-3-(2-furyl)- and 2-phenyl-3-[-(2-furyl)vinyl]-1,2-dihydronaphtho-[1,2-d]-1,2,4-triazines were obtained by heating Schiff bases [prepared by reaction of 1-(phenyl-azo)-2-aminonaphthalene with furfural, -(2-furyl)acrolein, and their 5-bromo and 5-nitro derivatives] in glacial acetic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 158–160, February, 1973.     

Synthesis of some substituted 2- and 4-[2′-(5″-nitro-2″-furyl)vinyl]-quinolines

A series of 2- and 4-[2-(5-nitro-2-furyl)vinyl]quinolines were synthesized by catalytic condensation of 5-nitrofurfural with 2- and 4-methylquinolines. 2-Methylquinoline (quinaldine) and its substituted derivatives also react when the starting reagents are fused directly.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 253–255, February, 1976.     

Synthesis and properties of 2-amino-5-(5-nitro-2-furyl) thiazole derivatives

The hydrochlorides of the corresponding 2-aminothiazoles, which were converted to the free bases, were obtained by hydrolysis of 2-acylamino-5-(5-nitro-2-furyl) thiazoles. Reactions that take place at the amino group of 2-amino-5-(5-nitro-2-furyl)thiazoles are described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1038–1041, August, 1985.     

Synthesis of 4-[3-(1H)-indolyl]-2-[N-guanidinomethyl]thiazole dihydrochloride

The title compound 3b was synthesized in three steps from acetaminothioacetamide ( 4b ) in 15% overall yield. This represents the first synthesis of a 2-guanidinomethylthiazole, which is a homolog of an important pharmacophore, 2-guanidinothiazole.     

X-ray diffraction study of 1-[1-benzoyl-2-(2-furyl)vinyl]-2-dicyanomethylene-1,2-dihydropyridine

1-[1-Benzoyl-2-(2-furyl)vinyl]-2-dicyanomethylene-1,2-dihydropyridine was studied by X-ray structural analysis. The compound under study occurs as aZ isomer with respect to the central vinyl fragment.     

Different specificities in the bromination of 6-(2-furyl)imidazo[2,1-b]thiazole and its derivatives with 1 mole of bromine

The action of 1 mole of bromine on 6-(2′-furyl)imidazo[2,1-b]thiazole, its 2-methyl-, 3-methyl-, and 2,3-dimethyl-substituted derivatives, and their hydrobromides in chloroform and glacial acetic acid was studied. The bromination of bases containing a methyl group in the 3 position leads primarily to the 5′-derivatives with respect to the furan ring in chloroform, whereas in the remaining cases 5-bromo derivatives with respect to the imidazothiazole system are formed. Compounds of the latter type are formed by the action of bromine in glacial acetic acid or of sodium hypobromite in alkaline media on the bases. The hydrobromides are brominated in both acetic acid and chloroform, regardless of the substituents in the thiazole ring, primarily in the 5′ position of the furan ring. The structures of the bromination products were proved by means of alternative syntheses, thin-layer chromatography, and the PMR spectra.     

Synthesis of 2-amino-4-(2-thienyl)thiazole and its derivatives

The bromination of substituted methyl 2-R-thienyl ketones with bromine in chloroform yielded bromomethyl 2-thienyl ketones. The latter were converted to quaternary pyridinium salts and 2-amino-4-(2-thienyl)thiazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1369–1371, October, 1971.     

Synthesis and biological activity of new 2-amino-4-[3-methyl-3-(5,6,7,8-tetrahydro-2-naphthyl)cyclobutyl]thiazole derivatives

2-Amino-4-[3-methyl-3-(5,6,7,8-tetrahydro-2-naphthyl)cyclobutyl]thiazole was synthesized by reaction of 1-methyl-1-(5,6,7,8-tetrahydro-2-naphthyl)-3-chloroacetylcyclobutane with thiourea in ethanol, and its subsequent transformations afforded new derivatives which were tested in vitro for antibacterial activity against some bacteria using the disk diffusion technique.__________From Zhurnal Organicheskoi Khimii, Vol. 40, No. 12, 2004, pp. 1861–1865.Original English Text Copyright © 2004 by Koparr, Cansz, Ahmedzade.The original article was submitted in English.     

Synthesis of bioactive 2-(2-(difluoromethoxy)aryl)benzo[d]thiazole derivatives via base-promoted one-pot process

A convenient synthesis of 2-(2-(difluoromethoxy)aryl)benzo[d]thiazoles from 2- (o-hydroxyaryl)benzothiazoles and commercially available ethyl difluoroiodoacetate (ICF₂CO₂Et) is described. The transformation was amenable to a one-pot, sequential three-component protocol from o-hydroxybenzaldehyde, o-aminothiophenol, and ICF₂CO₂Et promoted by KOH. Additionally, some of the prepared compounds exhibited promising activity against human ovarian cancer cells.