Chemistry and heterocyclization of dithiobiurea and thioureidoalkylthiourea (original) (raw)
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Molecules, 2005
Reactions of N,N`-disubstituted hydrazinecarbothioamides 8a-c and substituted thioureidoethylthioureas 9a-c with 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil, 10a) and 2,3,5,6-tetrabromo-1,4-benzoquinone (bromanil, 10b) to form N,N`-disubstituted [1,3,4]thiadiazole-2,5-diamines 11a-c, 6,7-dichloro-3-substituted amino-1H-benzo[1,3,4]thiadiazine-5,8-diones 12a-c, 2,3,7,8-tetrahalothianthrene-1,4,6,9-tetraones 13a,b, 5,6,8trihalo-7-oxo-3,7-dihydro-2H-quinoxaline-1-carbothioic acid substituted amides 14a-c, 15a-c and 7-substituted imino-[1,3,6]thiadiazepane-3-thiones 16a-c are reported. Rationales for the observed conversions are presented.
Journal of the Iranian Chemical Society, 2016
Various 1, 3-disubstituted thiourea derivatives are exceptionally flexible building blocks for the synthesis of a collection of heterocyclic compounds and exhibit a wide range of biological activities. Many thiourea derivatives exhibited remarkable antimicrobial activities [8]; 1, 3-dialkyl or diaryl thiourea derivatives showed significant antifungal activity against plant pathogens [9]. Experimental All chemicals purchased from Merck chemical company and used without further purification. 1 H NMR and 13 C NMR spectra were recorded on a Bruker Ultrashield-400 NMR spectrometer using DMSOd 6 as a solvent. IR spectra were recorded on a Bruker Tensor-27 FT-IR spectrophotometer using KBr pellets. Melting points were measured on an Electrothermal-9100 apparatus. Elemental analyses were run on a LECO-932 series. Synthesis of 1-(4-Amino-phenyl)-3-methyl-thiourea 1 A mixture of 1, 4-phenylene diamine (10 mmol) and methyl isothiocyanate (10 mmol) in 20 mL ethanol was heated at 60 °C. The promotion of the reaction was monitored by TLC. When the reaction was completed (90 min), the solvent was vaporized and remaining solid was washed with the mixture of hexane/ethyl acetate (9:1). The resultant precipitate was filtered and dried. After that, the precipitate was dissolved in 20% HCl solution and filtered. Then, 10% NaOH solution was added to the filtered solution until pH 7-8 was obtained and 1-(4-Aminophenyl)-3-methyl-thiourea 1 as a white precipitate was separated.
2018
Thiazols, triazines, imidazolidines, thiadiazines, thiazolidines and thiones are key structural motif and attracted considerable attention because of their applications in pharmaceutical and biological systems. Many of the scaffolds interestingly exhibits antiproliferative, anti-asthmatic, anti-inflammatory, anti-tubercular, anti-depressant, anti-cancer, antiviral, anti-ulcers, anti-hypertensives, antihistaminics, anti-diabetic, anti-protozoal, neuroprotective, anti-oxidant, and molluscicidal activities. Furthermore, literature explorations revealed that, much work have been reported on inter molecular cyclization reaction of thiourea with phenacyl bromide , chloroacetic acid, chloroacetyl chloride, and α,βunsaturated acid in various reaction condition. Synthesis of aza-heterocycles from N,N’-disubstituted thioureas and 2-phenyl-amino-thiazolines from (2hydroxyethyl)-phenylthioureas have been reported by intra molecular cyclization using TsCl/NaOH. The development of useful organic ...
Synthesis of thiadiazolobenzamide via cyclization of thioxothiourea and its Ni and Pd complexes
Journal of the Serbian Chemical Society, 2012
In this study, the new compound, N-(3-methyl-4- oxo[1,3,4]thiadiazolo[2,3-c][1,2,4]triazin-7-yl) benzamide, could be obtained via two different reactions: 1) reaction of 4-amino-6-Methyl-3- (Methylsulfanyl)-1,2,4-triazin-5-one with benzoyl isothiocyanate under removal of methylmercaptane, 2) reaction of 4-amino-6-Methyl-3-thioxo- 1,2,4-triazin-5-one with benzoyl isothiocyanate under elimination of hydrogen sulfide. In both reactions a new bond between sulfur and nitrogen atoms was formed and a five-membered ring was created. The oxo thiadiazolo benzamide was characterized by IR-, 1HNMR- and 13CNMR spectroscopy as well as by Mass spectrometry. X-ray crystallography was used to shed light on the structure of this new compound. Two new complexes could be generated by coordination of oxo thiadiazolo benzamide to Pd(II) and Ni(II) ions. These complexes have been analyzed by IR-, 1HNMR- and 13CNMR spectroscopy, conductometry and Thermal gravimetry (TGA). Theoretical QM Calculation GIAO ha...
International Journal of Scientific Research in Science and Technology, 2020
Thiazole represents important class of heterocyclic compounds. Thiazole and its derivatives have been reported to possess antitubercular, antibacterial, anti-inflammatory, anticancer, antifungal activity. Several methods of synthesis of thiazole derivatives have been reported, but most widely used synthetic approach to obtained thiazole derivatives is Hantzsch process. It involved synthesis of thiazole derivative from ?-halo-carbonyl compounds and thiourea or thiourea derivatives. This review mainly focuses on the research work reported in the scientific literature on the different procedures of synthesis of 2-amino thiazole and their derivatives.
Journal of the Iranian Chemical Society, 2015
In connection with our programme aiming to investigate the cyclization reaction of uracil bearing more reactive centers in addition to the possibility of pyrimidine ring transformation [1, 2, 21] we have tried to prepare some condensed pyrimidines. The starting material thiouracils 1a and 1b were obtained as described by [18, 19]. Thioxopyrimidine 1a undergo thiazole ring formation upon its reaction with chloroacetic acid and p-chlorobenzaldehyde in a mixture of acetic acid and acetic anhydride in the presence of fused sodium acetate to yield thiazolopyrimidine derivative 2. None of the expected products 3-5 were obtained (scheme 1). The formation of 2 is potentiated by the following facts: 1. Thermodynamically stable product. 2. The appearance of two carbonyl bands at 1761 and 1694 cm −1 in addition to cyano function at 2219 cm −1. 3. The absence of NH proton in 1 H NMR. The synthesis of N-cyanomethylpyrimidine derivative 6 was achieved by alkylation of compound 1a using chloroacetonitrile to give N-alkylated derivative 6. The structure of 6 was confirmed from IR spectrum that showed C≡N absorption band at 2224 cm −1 in addition to C=O band at 1686 cm −1. Moreover, the 1 H NMR spectrum showed two singlets at δ = 2.77 and 5.20 ppm corresponding to SCH 3 and CH 2 , respectively. Hydrazinolysis of 6 with hydrazine hydrate resulted in ring transformation affording diaminopyrimidine derivative 7. The formation of 7 was supported by 1 H NMR spectrum that showed three singlets at δ = 4.15, 4.41 and 11.50 ppm for NH 2 , CH 2 and NH, respectively.
A novel synthesis of heterocycles from thiocarbohydrazides
Monatshefte f�r Chemie Chemical Monthly, 1997
The reaction of thiocarbohydrazides la and thiocarbazones lb with tetracyanoethylene (TCNE) afforded the thiazol, thiadiazole, thiazine, and thiadiazepine derivatives 4 7. 2-Dicyanomethyleneindane-1,3-dione (CNIND) reacted with la,b to give aminoindenopyrazolopyridazinone (12) and phenyl-l,2,3,4-tetraazacyclopentafluorene (13). The indazole and oxathiadiazole derivatives 17 and 19 were formed during the reaction of lb with 2,3-dichloro-5,6-dicyano-l,4benzoquinone (DDO). 6,7-Dichloro-5-phenylpyrazolophthalazinol (21) was obtained from the reaction of lb with 2,3,5,6-tetrachloro-l,4-benzoquinone (CHL-p). The oxidative cyclization of thiodicarbazones 2a d with the above acceptors afforded the thiadiazole and thiadiazine derivatives 8 and 10.