The reaction of ethyl 4H-pyran-4-one-2-carboxylate with 1,2-diaminobenzene

Ethyl 4H-pyran-4-one-2-carboxylate was allowed to react with 1,2-diaminobenzene and related diamines. The resulting products were found to be 8H-5,6-dihydro-6,8-dioxopyrido[1,2-a]quinoxaline and derivatives. The synthesis 3H-5,6-dihydrobenzo[g]pyrido[1,2-a]quinoxaline-3,5-dione ( 2c ) constitutes the synthesis of a derivative of previously unknown benzo[g]pyrido[1,2-a]quinoxaline ring system.     

Preparation of 2,3-diaminopropionate from ring opening of aziridine-2-carboxylate

Ring opening reaction of an enantiomerically pure aziridine-2-carboxylate with an azide nucleophile under aqueous acidic media proceeded efficiently and stereoselectively to give 3-amino-2-azidopropionate which is converted to orthogonally protected 2,3-diaminopropionate.     

2,5-Dimethylcyclopentene-2-one-1

Conclusions 2,5-Dimethylcyclopentene-2-one-1 (V) was synthesized by bromination-dehydrobromination of 2,5-dimethyleyclopentanone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2211–2213, December, 1966.     

Synthesis of Methyl-6-methyl Tricyclo[5.2.1.02,6]decan-9-one-2-carboxylate: Potential Intermediate to Isocomene and Cuprenolide

A facile synthesis of methyl-6-methyl tricyclo [5.2.1.0^2,6]decan-9-one-2-carboxylate 7, a potential intermediate to isocomene 6 and cuprenolide 8 is described.     

Synthesis of heterocyclics based on 3-methoxy-2-acetylcyclohexene-2-one-1

Conclusions When 3-methoxy-2-acetylcyclohexene-2-one-1 is reacted with phenylhydrazine and hydroxylamiae, the corresponding cyclohexanopyrazole (IIa) and cyclohexanoisoxazole (IIb) are obtained.Translated from Izvestiya Akademii Nauk SSSK, Seriya Khimicheskaya, No. 12, pp. 2846–2847, December, 1969.     

KF-alumina 催化下2-氨基-4-芳基-5,6-二氢化-4H-吡喃[3,2-c]喹啉-5-酮-3-羧酸酯衍生物的一步合成

以芳醛、氰乙酸酯和4-羟基喹啉-2-酮为原料, 乙醇为溶剂, 在KF-Al₂O₃催化下80 ℃, 一步合成了2-氨基-4-芳基-5,6-二氢化-4H-吡喃[3,2-c]喹啉-5-酮-3-羧酸酯衍生物, 和其它方法相比, 具有反应条件温和, 容易操作和产率高等优点, 产物4a的结构通过X单晶衍射分析确证.     

Some aliphatic esters of benzoxazolin-2-one-3-carboxylic acid

Phosgene and benzoxazolin-2-one in the presence of diethylaniline gives benzoxazolin-2-one-3-carbonyl chloride. The latter and aliphatic alcohols, in the presence of a hydrogen chloride acceptor, gives esters of benzoxazolin-2-one-3-carboxylic acid.     

Synthesis of ethyl 2-alkylthio-2-oxazoline-5-carboxylate

Glycidic esters react with excess alkyl thiocyanates in the presence of equimolar amounts of boron trifluoride etherate to give esters of 2-alkylthio-2-oxazoline-5-carboxylic acids. The structure of the products was confirmed by the data from the PMR and IR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 460–461, April, 1979.     

Condensation of ethyl cydopentanone-2-carboxylate withN-arylmethylene-2-naphthylamines

The condensation of ethyl cyclopentanone-2-carboxylate withN-arylmethylene-2-naphthylamines depending on the conditions of reaction affords 4-aryl-l-ethoxycarbonyl-lH-2,3,4,5-tetrahydrocyclopenta-[c]benzo[f]quinolines, 4-aryl-l-ethoxycarbonyl-lH-2,3-dihydrocyclopenta[c]benzo[f]quinolines, and 4-aryllH-2,3-dihydrocyclopenta[c]benzo[f]quinolines.     

Synthesis and mesomorphic properties of some derivatives of 2-methylcyclohex-2-ene-4-one-1-carboxylic and cis-2,6-dimethyl cyclohex-2-ene-4-one-1 -carboxylic acids

Mesomorphic derivatives prepared from ethyl esters of 2-methylcyclohex-2-ene-4-one-1-carboxylic and cis-2,6-dimethylcyclohex-2-ene-4-one-1-carboxylic acids have been synthesized. It has been shown that the compounds obtained are characterized by a lower nematic—isotropic transition temperature (10-20°C) and a considerably narrower nematic range in comparison with the analogous derivatives of 4-alkylcyclohex-3-ene-carboxylic and trans-4-alkylcyclohexane-carboxylic acid.     

The reaction of benzylidenetriphenylphosphoranes with benzenediazonium-2-carboxylate

The title reaction affords to the adducts 3 which upon alkaline treatment give compounds 5 , while by thermolysis give 6 and 7 . Hydrochloride salts of 3 in refluxing xylene afford to chlorohydrazones 10 as the major products. A mechanism is proposed for thermal decomposition of 3.     

Practical preparation of ethyl 2-methylthiophene-3-carboxylate

A safe and efficient process for the preparation of ethyl 2-methylthiophene-3-carboxylate (5) was devised. This process provides several advantages over the precedents, involving operational simplicity, avoidance of the use of strong bases such as n-butyllithium and application of noncryogenic conditions, and enabled to prepare 5 in 52% overall yield from commercially available 2-methylthiophene on a multikilogram scale.     

Synthesis,Crystal Structure and Properties of Ethyl 3,9-Dimethyl-7-phenyl- 6H-dibenzo[b,d]pyran-6-one-8-carboxylate

Ethyl 3,9-dimethyl-7-phenyl-6H-dibenzo[b,d]pyran-6-one-8-carboxylate(C24H20O4, Mr = 372.40) has been synthesized and its structure was determined by 1H and 13C NMR, ESI-MS, elemental analysis, and X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P21/n, with a = 8.3674(11), b = 10.6683(14), c = 11.3817(15) , α = 95.596(2), β = 109.866(2), γ = 94.495(2)°, V = 944.2(2)3, Z = 2, Dc = 1.310 g/cm3, μ = 0.089 mm-1, F(000) = 392, R = 0.0482 and wR = 0.1281 for 2916 observed reflections with I 2σ(I). In the crystal structure, the fused tricyclic nucleus of the title compound is not fully coplanar. Analysis of the crystal packing indicates aromatic π-π stacking interactions occurring between the fused tricyclic aromatic rings of neighboring molecules in which a maximum overlap of the π-electron systems was achieved. Fluorescence and thermal studies indicate that compound 3 has good optical properties and thermal stability.