Synthesis and Structure of 5,5-Disubstituted N-[4-Methyl-3-phenylfuran-2(5H)-ylidene]-N′-phenylthioureas

Russian Journal of Organic Chemistry - The reaction of 5,5-disubstituted 4-methyl-3-phenyl-2,5-dihydrofuran-2-imines with phenyl isothiocyanate afforded...     

Derivatives of α,β-dehydro amino acids: VI. Reaction of 4-benzylidene-2-phenyl-1,3-oxazol-5(4H)-one with piperidin-2-ylmethanamine

4-Benzylidene-2-phenyl-1,3-oxazol-5(4H)-one reacts with piperidin-2-ylmethanamine to give N-{(Z)-3-oxo-3-[(piperidin-2-ylmethyl)amino]-1-phenylprop-1-en-2-yl}benzamide, N-(4-benzyl-3-oxooctahydro-2N-pyrido[1,2-a]pyrazin-4-yl)benzamide, or/and (Z)-4-benzylidenehexahydro-2H-pyrido[1,2-a]pyrazin-3(2H)-one, depending on the solvent, temperature, and reaction time. The latter product is formed via three-step tandem process.     

One-step synthesis of [4-(alkylsulfanyl)buta-1,3-diene-1-yl]-triphenylphosphonium iodides from buta-1,3-diene-1,4-diylbis(triphenylphosphonium) iodide

Buta-1,3-diene-1,4-diylbis(triphenylphosphonium) iodide reacted with alkanethiols at room temperature in the presence of triethylamine to give [4-(alkylsulfanyl)buta-1,3-diene-1-yl]triphenylphosphonium iodides and triphenylphosphine in high yields. Two presumable reaction mechanisms involving ethynylvinyl intermediate (formed via the Hofmann decomposition of the starting diiodide and the initially formed 1,4-adduct with a thiol) were discussed.     

X-Ray structural investigation of 1,3,6-trichloro-3,6-dimethylcycloheptanecarbonitrile and 2,5-dimethyl-2,5-dichlorohexane — Products of the reaction of 2,5-dimethyl-1,5-hexadiene with trichloroacetonitrile

Addition of trichloroacetonitrile to 2,5-dimethyl-1,5-hexadiene in the presence of cuprous amine complexes is studied. Single crystal X-ray diffraction unambiguously proves that the main product is a racemic mixture of the cyclic symmetric nitrile: (1r,3R,6S)-and (1r,3S,6R)-1,3,6-trichloro-3,6-dimethylcycloheptanecarbonitrile. Established relative configuration of the product confirms the ring closure mechanism suggested before. Also, a side product 2,5-dimethyl-2,5-dichlorohexane is isolated (the product of hydrochlorination of the starting alkadiene). Low-temperature (190 K) structural examination of this centrosymmetrical molecule indicates that the unit cell comprises one molecule.     

Synthesis of 1,2,4-triazole-3-thiols and their S-substituted derivatives

New 1,2,4-triazole-3-thiols were synthesized by reactions of the corresponding carboxylic acid hydrazides with isothiocyanates and subsequent cyclization of intermediate 1,4-substituted thiosemicarbazides. Alkylation of 1,2,4-triazole-3-thiols with benzyl chlorides and bromacetophenones gave only S-substituted derivatives.     

Synthesis and Structure of New Substituted Pyrimidinone with Unsaturated Side Chain

Melting of a mixture of 5-substituted 2,4-dimethyl-1,6-dihydropyrimidin-6-ones with cinnamic aldehyde, 1-methylindoline-2,3-dione and 6-methoxy-2-chloroquinoline-3-carbaldehyde in the presence of ZnCl₂ led to the formation of substituted pyrimidines with conjugated bonds in the position 2. The structure of synthesized compounds as 2-isomers was confirmed by 2D ¹H NMR NOESY data.     

Monoclinic La1−xBaxMnO3 (x = 0.185) at 160 K

Single‐crystal X‐ray diffraction has shown that lanthanum barium manganese trioxide, La_0.815Ba_0.185MnO₃, is monoclinic (I2/c) below a first‐order phase transition at 187.1 (3) K. This result differs from the Pbnm symmetry usually assigned to colossal magnetoresistance oxides, A_1−xA′_xMnO₃ with x≃ 0.2, which adopt a distorted perovskite‐type crystal structure. The Mn atom lies on an inversion center, the disordered Li/Ba site is on a twofold axis and one of the two independent O atoms also lies on a twofold axis.     

Derivatives of α,β-dehydroamino acids: V. Intramolecular cyclization of 2-{2-[(<Emphasis Type="Italic">Z</Emphasis>)-1-Benzamido-2-phenylvinyl]acetamidomethyl}benzimidazole

Reaction of 4-benzylidene-2-phenyl-1,3-oxazol-5(4H)-one with 2-(1H-benzimidazol-2-yl)ethaneamine led to the formation of 2-{2-[(Z)-1-benzamido-2-phenylvinyl]acetamidomethyl}benzimidazole that in a reaction with hexamethyldisilazane in DMF gave 5-benzylidene-1-(1H-benzimidazol-2-yl)-2-phenyl-3,5-dihydro-4H-imidazol-4-one. In the presence of K₂CO₃ in dioxane the reaction with hexamethyldisilazane resulted in the product of intramolecular addition, N-(4-benzyl-3-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]-benzimidazol-4-yl)benzamide     

Synthesis and Anticholinesterase Activity of [(4<Emphasis Type="Italic">Z</Emphasis>)-2-Aryl-4-(arylmethylidene)-5-oxo-4,5-dihydro-1<Emphasis Type="Italic">H</Emphasis>-imidazol-1-yl]alkanoic Acids

ω-[(4Z)-2-Aryl-4-arylmethylidene-5-oxo-4,5-dihydro-1H-imidazol-1-yl]alkanoic acids were synthesized by reaction of N-substituted α,β-dehydropeptides with chloro(trimethyl)silane or 1,1,1,3,3,3-hexamethyldisilazane. Both initial peptides and (4H)-imidazol-5-one derivatives based thereon were tested for anticholinesterase activity.     

X-Ray Investigation of (E)-2-phenyl-1-chlorocyclopropane-1-carboxylic Acid — A Convenient Synthon for Transamine Synthesis

A method for the synthesis of (E,Z)-2-phenyl-1-chlorocyclopropane-1-carboxylic acid by the addition of ethyl trichloroacetate to styrene in the presence of copper(I) ammine complexes is suggested. The major isomer was isolated as the corresponding acid. The results of X-ray diffraction (XRD) analysis unequivocally prove that the benzene ring and the carboxylic group are in the cis-position and that the molecules form centrosymmetric dimers. (E)-2-phenyl-1-chlorocyclopropane-1-carboxylic acid can serve as a convenient synthon for transamine synthesis.