Synthesis and Crystal Structure of N-（2-（1,3,4-oxadiazol-2-yl）phenyl）-2,3-dimethylaniline

The title compound, N-（2-（1,3,4-oxadiazol-2-yl）phenyl）-2,3-dimethylaniline, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, ^1H- and ^13C-NMR spectroscopy, elemental analysis and mass spectrometry. These experimental studies were supported by theoretical optimizations.     

Synthesis of N-Aryl-N′- (5-aryloxymethyl-1,3,4-thiadiazol-2-yl) ureas under Microwave Irradiation

The rapid heating effect of microwave irradiation has caught the attention of synthetic chemists in the recent times due to the remarkable reduction of reaction time. It is an efficient method because of its virtue of rapid heating capability, high yield and simple procedure. The superiority of these virtues goes beyond of traditional heating reaction.     

Synthesis and Characterization of New Thebaine Derivatives: 2-(6,14-endo-Ethenotetrahydrothebaine-7α;-yl)-5-(N-Arylamino)-1,3,4-Thiadiazoles

Abstract

We have synthesized a series of novel 2-(6,14-endo-ethenotetrahydrothebaine-7α-yl)-5-N-arylamino-1,3,4-thiadiazoles (5a–n) as potential narcotic analgesics, which are analogs of morphine. The synthesized compounds exhibit rigid morphine structures, including a 6,14-endo-entheno bridge and a 5-N-arylamino-1,3,4-thiadiazol-2-yl group at C-7 position that adopted S-configuration. The structures and stereochemistry of the compounds were completely assigned using one- and two-dimensional NMR experiments (¹H NMR, APT, COSY, NOESY, HMQC, and HMBC), FTIR, and high-resolution mass spectral (HRMS) data.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and photochromism of dimers of 4,5- diaryl-2-(2,5-dimethylthiophen-3-yl)imidazolyl

4,5-Diphenyl, 4,5-di(4-methylphenyl), 4,5-di(4-methoxyphenyl)-2-(2,5-dimethylthioph-en-3-yl)imidazoles were synthesized. Oxidation of the obtained imidazoles with potassium ferricyanide in water-alcohol solution of alkali gave the corresponding dimers. The structures were characterized by IR, 1H NMR, mass spectroscopy and elemental analysis. The dimers showed photochromism in solution on irradiation.     

Synthesis and ozonization of (+)-4α-(1-trimethylsilyloxyethen-1-yl)-2-carene

(+)-4-(1-Trimethylsilyloxyethen-1-yl)-2-carene was synthesized, and the products of its ozonization were identified.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1984–1987, October, 1995.     

Synthesis of 2-(hydroxyphenylamino)- and 2-(aminophenylamino)-4-methylquinolines and N,N′-bis(4-methylquinolin-2-yl)benzenediamines

2-(Hydroxyphenylamino)- and 2-(aminophenylamino)-4-methylquinolines and N,N′-bis(4-methylquinolin-2-yl)benzenediamines were synthesized by reactions of 2-chloro-4-methylquinolines with o-, m-, and p-aminophenols and o-, m-, and p-phenylenediamines.     

Synthesis of N-(2-chloroethyl)isatins and their β-ethyleneacetals and β-thiosemicarbazones

The nitrogen atoms of isatin, its 5-bromoderivative, and their -ethyleneacetals are alkylated by 1,2-dichloroethane in K₂CO₃–DMF and LiH(NaH)-DMF.Institute of Biological Protection of Plants and Institute of Chemistry of the Moldovan Academy of Sciences, Kishinev 2058. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 907–909, July, 1999.     

Synthesis,Crystal Structure and Biological Activity of 2-（Anthracen-9-yl）-5-p-tolyl-1,3,4-oxadiazole

A novel compound,2-(anthracen-9-yl)-5-p-tolyl-1,3,4-oxadiazole(C23H16N2O),has been synthesized by the condensation of 4-methylbenzohydrazide and anthracene-9-carbaldehyde in an ethanol solution with chloramine-T.The compound was characterized by 1H-NMR,13C-NMR,MS and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P with a = 7.7817(4),b = 8.8544(5),c = 12.4726(8) ,β = 92.8520(10)°,Z = 2,V = 826.58(8) 3,Dc = 1.352 g/cm3,Mr = 336.38,λ(MoKα) = 0.71073 ,μ = 0.084 mm-1,F(000) = 352,R = 0.0381 and wR = 0.1099.The dihedral angle between anthracene skeleton and phenyl ring is 64.19°.A total of 6354 unique reflections were collected,of which 3172 with I > 2σ(I) were observed.X-ray analysis indicated an offset face-to-face π-π stacking interaction between anthracene skeletons and an offset face-to-face π-π stacking interaction between phenyl ring planes.The novel compound molecules are connected through the offset face-to-face π-π stacking interactions to generate a three-dimensional network.The preliminary bioassay results showed that the novel compound exhibited significant insect growth inhibitory activity against Spodoptera litura Fabricius larvae.     

Synthesis and mesomorphic properties of 2-(4′-alkoxybiphenyl-4-yl)-1H-benzimidazole derivatives

Three series of 2-(4′-alkoxybiphenyl-4-yl)-1H-benzimidazole derivatives (nM-x), which possessed 5-nitrobenzimidazole (nM-N series), benzimidazole (nM-H series) or 5-methylbenzimidazole (nM-M series) units at the end of the molecule, were synthesised and characterised by infrared, ¹H- and ¹³C-nuclear magnetic resonance spectra, electrospray ionisation-mass spectrometry and elemental analysis. Their phase transition behaviour was investigated by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. All the compounds exhibited enantiotropic smectic mesophases with wide temperature domains for a carbon number in the alkoxy chain from 6 to 16, where the mesophase ranges were 14–91°C and 17–99°C during heating and cooling processes for the nM-N compounds, 7–25°C and 8–49°C for the nM-H compounds and 48–81°C and 52–85°C for the nM-M compounds, respectively. The effect of the length of alkoxy chain on mesomorphic properties was discussed. The nM-N and nM-M exhibited a much wider mesophase range whether during heating or cooling process than the corresponding nM-H series, especially for the longer terminal chain (n > 8), which indicated that the substituent in the benzimidazole moiety was helpful in increasing the mesophase stability.     

Synthesis and Crystal Structure of 2,5-Di- （pyridin-3-yl）-1,3,4-oxadiazolendium Nitrate

In order to continue our studies on the synthesis, properties and coordination of s-tetrazine, 3,6-di-(pyridin-3-yl)-s-tetrazine (II, 3-dptz) was synthesized and characterized by 1H- NMR, MS and IR spectra. And the coordination reaction of 3-dptz with nitrate of Cu(II) was studied. 3-dptz reacting with CuII salt [Cu(NO3)2·2H2O] generates a new salt, nitrate of 2,5-di-(pyridin-3- yl)-1,3,4-oxadiazolene (III). III was determined by IR spectra and single-crystal X-ray diffraction to give the following crystal data: space group P21/c, a = 4.9112(1), b = 8.4101(3), c = 29.499(1) , β = 93.266(2)o, V = 1216.44(7) nm3, Mr = 287.24, Z = 4, Dc = 1.568 g/cm3,μ= 0.122 mm-1, F(000) = 592, R = 0.0430 and wR = 0.1240. The results show that III is composed of one cation and one nitrate anion. The cation consists of one H+ and one 2,5-di-(pyridin-3-yl)-1,3,4-oxadiazol molecule, with the former being attached to the latter via electrovalent bond with N3 atom. And the O(42) atom in the nitrate anion is disordered. Intra- and intermolecular H-bonds are observed in the crystal of the title compound. The mechanism of metal-assisted decomposition was also discussed briefly.     

Synthesis and cyclization of N-(9-alkylcarbazol-3-yl)-β-alanines

The reaction of 3-amino-9-alkylcarbazoles with acrylic and itaconic acids yields N-substituted amino acids, which were converted into derivatives of 4-carboxy-2-pyrrolidinone and dihydropyrimidinedione.Kaunas Technological University 3028 Kaunas, LithuaniaTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1637–1640, November–December, 1999.     

Synthesis and Characterization of 4′-Bromomethyl-2-(N-trityl-1H-tetrazol-5-yl) Biphenyl

Biphenyl tetrazole ring is an important component of the Sartan family of novel drugs. 4′-Bromomethyl-2-(N-trityl-1H-tetrazol-5-yl)biphenyl was synthesized in this article from 4′-methyl-2-cyano-biphenyl through three steps. 4′-Methyl-2-cyano-biphenyl was reacted with azide ions with the help of ammonium chloride as catalyst in an autoclave with high conversion to afford the tetrazole compounds in 70.6% yield. After being protected by the trityl group with 92.6% yield, 4′-methyl-2-(N-trityl-1H-tetrazol-5-yl) biphenyl was brominated with N-bromosuccinimide (NBS) in cyclohexane with 2,2′-azo-isobutyronitrile (AIBN) acting as an initiator to provide the title compound in 83.8% yield.     

Synthesis and properties of 5-furyl(aryl)-Δ2-1,2,4-triazolines and -Δ2-1,3,4-thiadiazolines. Molecular and crystal structure of 2-acetylamino-5-phenyl-Δ2-1,3,4-thiadiazoline

We show that upon acylation of arylidene amidrazones of 5-nitro-2-furancarboxylic acid, 3-(5-nitro-2-furyl)-²-1,2,4-triazolines or 5-(5-nitro-2-furyl)-1,2,4-triazole are formed (depending on the structure of the arylidene moiety). ²-1,3,4-thiadiazolines are obtained by reaction of thiosemicarbazones of aromatic and furaldehydes and furan ketones. We discuss schemes for closure of the triazolidine, triazole, and thiadiazoline rings. We describe the molecular structure of 2-acetylamino-4-acetyl-5-phenyl-²-1,3,4-thiadiazoline.Kuban State Technological University, Krasnodar 350072. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1337–1344, October, 1994. Original article submitted October 11, 1994.     

Synthesis and Structure of 2-(1Н-Indol-1-yl)-6-ferrocenyl-4-(2-chloroimidazo[1,2-a]pyridin-3-yl)pyrimidine

A 2,4,6-trisubstituted pyrimidine including a 2-(1H-indol-1-yl) substituent was synthesized by the reaction of 1-ferrocenyl-3-(2-chloroimidazo[1,2-a]pyridin-3-yl)propanone with 2,5-dimethoxytetrahydrofuran. The structure of the synthesized compound was confirmed by IR and ¹Н NMR spectroscopy, and X-ray diffraction analysis. It has been shown that the ferrocene-containing compounds synthesized in the present work all demonstrate intramolecular charge transfer which is evidenced by the observation of the corresponding absorption bands with λ ^abs_max > 480 nm. The oxidation potential of ferrocene (E ^Fc_ox ) in all the compounds is higher than 700 mV.

     

Synthesis and Structure Determination of (2S, 2′S)-3-Phenyl-2-(pyrrolidin-2′-yl)- propionic Acid

Abstract

Aβ²,β³-homoproline derivative, (2S, 2′S)-3-phenyl-2-(pyrrolidin-2′-yl)propionic acid, was synthesized starting from l-proline. After preparation of the (4S, 4aS)-4-benzyl-4a,5,6,7-tetrahydro-pyrrolo-[1,2-c]pyrimidine-1,3-dione under a mild condition, the absolute configuration of target compound was assigned using 2D H-H COSY and H-H NOESY technologies.     

Synthesis of chiral 2-(2′-pyrrolidinyl)pyridines from (S)- and (R)-proline: potential ligands of the neuronal nicotinic acetylcholine receptors

A new strategy for a straightforward synthesis of novel optically active nicotine analogues starting from (S)- and (R)-proline is reported utilizing as the key steps the inverse electron demand Diels–Alder reaction of, hitherto unknown, chiral 5-(2′-pyrrolidinyl)-1,2,4-triazines (S)- and (R)-16. These serve as appropriate precursors for the preparation of different, highly enantiomerically enriched 2-(2′-pyrrolidinyl)pyridines, modifications of natural (−)-nornicotine and (−)-nicotine and potential ligands of the neuronal nicotinic acetylcholine receptors. The multistep syntheses proceed under mild conditions, with good overall yields and with stereochemical integrity of the original stereogenic centers.     

Synthesis of β-(о-hydroxybenzyl)pyridines by three-component condensation of ammonia,carbonyl-substituted 4Н-chromenes,and СН acids

Chemistry of Heterocyclic Compounds - A series of pyridine derivatives containing a 2-hydroxybenzyl or (2-hydroxynaphthalen-1-yl)methyl substituent were obtained by treating carbonyl-substituted...