- Facile synthesis of phthalidyl fused spiro thiohydantoins through silica sulfuric acid induced oxidative rearrangement of ninhydrin adducts of thioureas
-
A one-pot three-component sequential synthetic protocol produces structurally and biologically important phthalidyl fused spiro N,N′-disubstituted thiohydantoins from readily available aromatic isothiocyanates, primary amines and ninhydrin. In this three-step synthesis while the initial two steps are catalyst-free, in the final step silica sulfuric acid (SSA) induces an oxidative rearrangement in [3.3.0]-bicyclic 1,2-diol adducts of ninhydrin and thioureas under solvent-free condition to generate the final products spiro-fused thiohydantoins. The adequate acidity of SSA in cooperation with moderate oxidizing property promotes a facile oxidative rearrangement in 1,2-diol intermediates to produce the spiro-fused thiohydantoins with diverse functionalities. Easy recyclability of SSA, good to excellent yield of the products, wider substrate scope, shorter reaction time, solvent-free two steps out of three and high atom economy make this method attractive and practicable.
- Mandal, Subhro,Pramanik, Animesh
-
-
- Synthesis of novel dithiocarbamates and xanthates using dialkyl azodicarboxylates: S–N bond formation
-
A one?pot three?component route for the synthesis of a novel category of dithiocarbamates or xanthates is developed by a reaction of in-situ generated dithiocarbamic acids or xanthates with dialkyl azodicarboxylates under mild and catalyst-free conditions. The reaction is characterized by a wide scope, high efficiency and straightforward isolation protocol. The synthetic utility of the dithiocarbamates and xanthates was demonstrated on the preparation of symmetrical and unsymmetrical thioureas, isothiocyanates, and thiocarbamates.
- Ziyaei Halimehjani, Azim,Klepetá?ová, Blanka,Beier, Petr
-
p. 1850 - 1858
(2018/03/06)
-
- Reactions of N-alkenyl Thioureas with p-alkoxyphenyltellurium Trichlorides
-
N-Аlkenyl thioureas, under the action of aryltellurium trichlorides, form the addition products N-{2-chloro-3-[dichloro(4-alkoxyphenyl)-tellanyl]propyl} thioureas or the intramolecular cyclization products 5-{dichloro(4-alkoxyphenyl)-telluromethyl}-2-phenylamino-4,5-dihydro-1,3-thiazole hydrochlorides. The reaction route depends on the nature of the substituent in the thiourea. The Fukui function reactivity indexes identify the electrophilic/nucleophilic centers and explain the possible cyclization reaction in the case of phenyl substituted thioureas. In the case of other substituents, the calculated values of partial atomic charges clearly predict that the addition reaction is more possible.
- Kut, Mykola,Fizer, Maksym,Onysko, Mikhajlo,Lendel, Vasil
-
p. 2284 - 2290
(2018/09/06)
-
- Synthesis, characterization, and antibacterial activity of some thiazoles derived from allyl thioureas
-
Synthesis of thiazoles was carried out from allyl thioureas using different cyclizing agents such as hydrogen chloride gas and bromine. Synthesized compounds were characterized by IR, 1H and 13C NMR, mass spectrometry, and elemental analysis. The synthesized thiazoles were evaluated for their antibacterial activity against Gram postitive (Lactobacillus bulgaris and Streptococcus mitis) and Gram negative (Yersinia) as well as antifungal activity against Aspergillus niger fungi.
- Khare,Sharma,Sharma
-
p. 702 - 707
(2016/06/01)
-
- Synthesis, molecular docking and biological evaluation of N,N-disubstituted 2-aminothiazolines as a new class of butyrylcholinesterase and carboxylesterase inhibitors
-
A series of 31 N,N-disubstituted 2-amino-5-halomethyl-2-thiazolines was designed, synthesized, and evaluated for inhibitory potential against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and carboxylesterase (CaE). The compounds did not inhibit AChE; the most active compounds inhibited BChE and CaE with IC50 values of 0.22-2.3 μM. Pyridine-containing compounds were more selective toward BChE; compounds with the para-OMe substituent in one of the two dibenzyl fragments were more selective toward CaE. Iodinated derivatives were more effective BChE inhibitors than brominated ones, while there was no influence of halogen type on CaE inhibition. Inhibition kinetics for the 9 most active compounds indicated non-competitive inhibition of CaE and varied mechanisms (competitive, non-competitive, or mixed-type) for inhibition of BChE. Docking simulations predicted key binding interactions of compounds with BChE and CaE and revealed that the best docked positions in BChE were at the bottom of the gorge in close proximity to the catalytic residues in the active site. In contrast, the best binding positions for CaE were clustered rather far from the active site at the top of the gorge. Thus, the docking results provided insight into differences in kinetic mechanisms and inhibitor activities of the tested compounds. A cytotoxicity test using the MTT assay showed that within solubility limits (30 μM), none of the tested compounds significantly affected viability of human fetal mesenchymal stem cells. The results indicate that a new series of N,N-disubstituted 2-aminothiazolines could serve as BChE and CaE inhibitors for potential medicinal applications.
- Makhaeva, Galina F.,Boltneva, Natalia P.,Lushchekina, Sofya V.,Serebryakova, Olga G.,Stupina, Tatyana S.,Terentiev, Alexey A.,Serkov, Igor V.,Proshin, Alexey N.,Bachurin, Sergey O.,Richardson, Rudy J.
-
p. 1050 - 1062
(2016/02/19)
-
- A versatile thiouronium-based solid-phase synthesis of 1,3,5-triazines
-
A thiouronium-based solidphase synthesis of a 1,3,5-triazine scaffold has been developed. The key feature of the synthesis is the use of a readily accessible solid-supported thiouronium salt as a primary precursor for the stepwise assembly of the 1,3,5-tri-azine substrate. The sulfur linker employed in the synthesis is stable under both acidic and basic conditions and is versatile enough to provide access to monocyclic, bicyclic, and spirocyclic compounds with the 1,3,5-triazine scaffold. By using this synthetic strategy, a representative set of 79 compounds containing the 1,3,5-triazine scaffold were prepared.
- Kong, Kah Hoe,Tan, Chong Kiat,Lin, Xijie,Lam, Yulin
-
experimental part
p. 1476 - 1486
(2012/03/26)
-
- A convenient route to cyanoguanidines
-
A facile and versatile method for the preparation of cyanoguanidines 7 from amines 3 and isothiocyanates 4 via a methylation, cyanamide-treatment sequence is described.
- Novak, Lajos,Hanania, Michel,Kovacs, Peter,Kovacs, Csilla Erika,Kolonits, Pal,Szantay, Csaba
-
p. 1757 - 1766
(2007/10/03)
-
- Structure and hydrogen bonding of solid N1-alkyl-N2-arylthioureas. 13C CP/MAS, IR and semi-empirical AM1 studies
-
Seven crystalline N1-alkyl-N2-arylthioureas were studied by 13C CP/MAS NMR and by IR spectroscopy. The double set of signals in 13C CP/MAS spectra indicates that molecules of N1-ethyl-N2-(3-methylphenyl)thiourea and N1-ethyl-N2-(4-methylphenyl)thiourea are crystallographically non-equivalent. N1-Propene-N1-phenylthiourea forms cyclic dimers with two N2-H...S hydrogen bonds, as confirmed recently by x-ray diffraction. The broad vNH maxima at 3175-3295 cm-1 in the IR spectra indicate that in other thioureas both N1-H and N2-H protons are involved in hydrogen bonding and that the non-bonded N1-H proton in cyclic dimers of N1-propenethioureas is probably an exception. Semi-empirical AM1 calculations showed that the N2-H proton is more positively charged than the N1-H proton and therefore should be preferentially involved in N2-H...S hydrogen bonds.
- Wawer, Iwona,Koleva, Vera
-
p. 207 - 212
(2007/10/03)
-
- Manganese dioxide in a new role of Sulfur extrusion in thioamides
-
A simple and efficient procedure for the mild conversion of thioamides to amides in good yields using active manganese dioxide is described.
- Radha Rani,Rahman,Bhalerao
-
p. 1953 - 1958
(2007/10/02)
-
- Enzymatic Oxidative Conversion of Thio to Oxo by Baker's Yeast in Thiocarbamates and Thioureas
-
The enzymatic conversion of aryl allylthiocarbamates and 1-allyl-3-arylthioureas by baker's yeast to the corresponding carbamates and ureas in good yields is described.
- Kamal, Ahmed,Rao, Maddamsetty V.,Rao, Adari B.
-
p. 655 - 656
(2007/10/02)
-
- Influence of Substituents on the Synthesis of Thiazolidinones
-
The influence of substituents (subunits) in the synthesis of thiazolidinones by the reaction of unsymmetrical thioureas with monochloroacetic acid in ethanol has been rationalised by the characterisation of the hydrolysis products of the resulting thiazolidinones.The formation of thiol from thiourea, which is the key intermediate in thiazolidinone synthesis, invariably involves the -NH- group adjacent to more electron withdrawing subunits.
- Sabu, M.,Garnaik, B. K.,Behera, Rajani K.
-
p. 779 - 781
(2007/10/02)
-
- Synthesis of N-Allyl-2-oxocycloalkanecarbothioamides, Functionalised Organic Intermediates via Enamines
-
Cyclopent-1-enylmorpholine (1a)/pyrrolidine (1b) and cyclohex-1-enylpyrrolidine (1c)/aniline (1d) with allyl isothiocyanate furnish N-allyl-2-oxo-cyclopentane- and N-allyl-2-oxocyclohexanecarbothioamides (3,n = 3/4), respectively after hydrolysis of the product mixture.
- Singh, Harjit,Singh, Paramjit,Mehta, R. K.
-
p. 1048 - 1049
(2007/10/02)
-