The molecular structure of 4a, 5, 8, 8a-tetrahydro-11, 14-dimethoxy-7-methyl-4a-(3-methyl-2-butenyl)-5, 8a-o-benzeno-1, 4-naphthoquinone

A novel natural product, microphyllone, has been isolated from Ehretia microphylla² together with baurenol and ursolic acid. Spectroscopic techniques, derivative formation and finally X-ray diffraction have been utilized in the structure elucidation of microphyllone. The structure appears to be 4a, 5, 8,8a - tetrahydro -11,14- dihydroxy-7-methyl-4a-(3-methyl-2-butenyl)-5, 8a-o-benzeno-1, 4-naphthoquinone.     

β-甲萘醌催化氧化合成技术研究进展

综述了不同原料合成K系维生素重要中间体β-甲萘醌的不同方法及相应催化氧化体系建立的研究进展。与传统工业生产工艺相比较,着重分析以β-甲基萘为原料所采用的各催化剂类别及其催化氧化合成路线的特点和不足;结合国内外催化材料使用和国内生产现状,提出环境友好绿色催化氧化合成β-甲萘醌的未来发展趋势及研究方向。     

Preferable tautomer of dihydropyrazolo[5, 1-c][1, 2, 4]triazines in solution

Dihydropyrazolo[5, 1-c][1, 2, 4]triazines 6, 7 and 8 were found to predominate as the 4, 6-dihydro tautomeric form in solution by the measurement of ID NOE different spectra.     

Synthesis of 1-aryl-5-methyl-4-substituted-l,2,3-triazoles

As 1-aryl-5-methyl-4-substituted-1,2,3-triazoles often exhibit broad spectrum biological actions, we have synthesized many heterocyclic and condensed heterocyclic compounds which contained 1-aryl-5-methyl-1,2,3-triazol-4-yl functional groups and screened their antibacterical activities^[1,2]. Our further work testified that it was necessary to go on studying such kind of compounds. In order to improve the soluble of these compounds, we chose aniline and p-toluidime as starting materials to synthesize 1-aryl-5-methyl-4-substituted-1,2,3-triazoles 1a-b, 2a-b, 3a-b, 4a-b, 5a, These new compounds all have active reaction groups such as SH, NH₂ as well as OH. So they might react with ω-substituted-ω-bromo-acetophenone and 6a-b, 7a-b, 8a-b, 9a were obtained. They are all soluble in hot alcohol. Under similar conditions it is difficult to let 4a-b react completely with ω-substituted-ω-bromo-acetophenone. We only observed a little new compounds by TLC. By Mannich reaction, 1a-b also could react with formaldelyde and p-toluidime and l0a-b were isolated. The evaluation of the biological activity is in progress.     

The Synthesis of 4-Alkyldithioate-5-hydroxy-3-methyl-1-phenylpyrazoles

The title pyrazoles (2)-(8) were obtained by the condensation of 3-methyl-1-phenyl-2-pyrazoline-5-one (1) with carbon disulfide and primary alkyl halides, in the presence of n-butyllithium.     

Syntheses of 1beta-methylcarbapenems bearing 5-methyl-4-hydroxypyrrolidinone

A new series of 1beta-methylcarbapenems 1a-d bearing 5-methyl-4-mercaptopyrrolidinone rings has been prepared and evaluated for in vitro antibacterial activity and pharmacokinetic parameters. Most compounds showed excellent antibacterial activity and high stability to dehydropeptidase-1. We have synthesized optically active 5-methyl-4-hydroxypyrrolidinones from enantiomerically pure aziridine esters.     

3-正丙基-4-氨基-5-酰胺基-1-甲基吡唑的合成

以2－戊酮为起始原料，经Claisen缩合、环化、甲基化、皂化、硝化、酰胺化和还原反应，制得目标化合物。总收率比文献报道值提高一倍，达46．8％。     

Dehalogenation of 1-methyl-5-halo-4-substituted-pyridazin-6-ones

In order to confirm the regiochemistry for the functionalization of 1-(1,1-dibromo-2-oxopropyl)-4,5-dihalopyridazin-6-ones, the dehalogenation of 1-methyl-5-halo-4-substituted-pyridazin-6-ones using Pd/C and hydrogen was carried out. The results of the title reaction are reported.     

Tautomerism of 1-phenyl-3-methyl-4-benzyl-5-pyrazolone

The tautomerism of 1-phenyl-3-methyl-4-benzyl-5-pyrazolone —a side product in the reaction of acetoacetic ester with benzaldehyde phenylhydrazone — was studied by IR and PMR spectroscopy, and its thermodynamic characteristics were determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 355–359, March, 1991.     

Synthesis and reactions of 1-methyl-5-tributylstannyl-4-trifluoromethylpyrazole

N-Methylation at the pyrazole ring by sequential treatment of 5-tributylstannyl-4-trifluoromethylpyrazole with LDA and iodomethane regioselectively provided the title compound in high yield. The addition reaction of 5-lithiated-4-trifluoromethylpyrazole with a wide range of electrophiles allowed easy and high-yielding introduction of substituents on position 5.     

Structural,spectral, and theoretical investigations of 5-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid

Research on Chemical Intermediates - The present research work has focused on combined experimental and theoretical studies of one of the biologically important pyrazole-4-carboxylic acid...     

Phase-transfer oxidation of 2-methyl-1-naphthol into 2-methyl-1,4-naphthoquinone in the presence of vanadomolybdophosphoric heteropolyacids

2-Methyl-1-naphthol is oxidized into 2-methyl-1,4-naphthoquinone (menadione) by air in the presence of vanadomolybdophosphoric heteropolyacids and their salts. The reaction proceeds in a biphasic system, and the yield of menadione is up to 85 %. The influence of the composition of the heteropolyacids on the rate and the selectivity of the reaction was studied, and the reaction mechanism was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1208–1211, July, 1994.     

Formation and structure of 1-Amino-4-methyl-4-(4-methyl-5-phenyl-1H-pyrazol-3-ylamino)-3-phenyl-4,5-dihydro-1H-pyrazol-5-one

The title compound 3 was obtained during the rearrangement of isoxazol-5-yl hydrazine 1 to 1-aminopyrazolone 2 at 115°. X-ray analysis of the corresponding benzylidene derivative allowed us to achieve the structure assignment.     

1-甲基-4-硝基-5-氯咪唑的合成新工艺研究

1-甲基-4-硝基-5-氯咪唑是合成免疫抑制剂硫唑嘌呤(Azathioprine)的中间体.硫唑嘌呤可抑制人体内淋巴细胞,减少狼疮病人的免疫复合物在肾脏的沉积,抑制局部炎症.同时用于治疗类风湿关节炎、各种血管炎、多发性肌炎皮肌炎及系统性红斑狼疮等.