Synthesis and characterization of 5-bromo-3-sec-butyl-6-methyluracil

A new synthetic method for 5-bromo-3-sec-butyl-6-methyluracil (Bromacil) using 2-bromobutane and urea as starting materials is described. The synthesis involved condensation, cyclization and bromination with a total yield of 60%. The structure of Bromacil was determined by ¹H NMR, ¹³C NMR and IR spectroscopy. __________ Translated from Journal of Shandong University (Natural Science Edition), 2007, 42(7): 9–12 [译自: 山东大学学报(自然科学版)]     

Alkyl 3-fluoroalkyl-3-oxopropionates in reactions with azolyldiazonium salts

Alkyl 3-fluoroalkyl-3-oxopropionates react with antipyrinyldiazonium chloride to form 2-antipyrinylhydrazono-3-fluoroalkyl-3-oxopropionates. The use in these reactions of hetaryldiazonium salts, containing NH group in the α position, leads to alkyl 7-fluoroalkyl-7-hydroxy-4,7- dihydroazolo[5,1-c]triazine-6-carboxylates. 3-Amino-1H-1,2,4-triazole, 3-amino-4-ethoxycar- bonyl-1H-pyrazole, and 5-amino-4-ethoxycarbonyl-1H-imidazole were used as the heterocyclic component. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 599–603, March, 2008.     

3,13-二羟基-1,5,8,11,15,18-六氮杂环二十烷的合成研究

尝试了三种制备 3 ,13 二羟基 1,5 ,8,11,15 ,18 六氮杂环二十烷 ( 5 )的方法 .实验结果表明 1,3 二氯 2 丙醇 ( 1)与N 对甲苯磺酰基 -二乙烯三胺 ( 2 )在醇钠条件下制备 5的方法简便可行 ,易于纯化 ,收率较高     

12H-13-氧(硫)-苯并环庚并[1,2-b]

2-苯氧(硫)甲基-3-喹啉酸(1a-e)可以在Eaton's reagent (P2O5-MeSO3H) 的作用下进行分子内的闭环反应得到12H-13-氧(硫)-苯并环庚并[1,2-b]喹啉-5-酮类衍生物(2a-e).该环化工艺比传统的环化工艺所要求的反应条件更加温和,具有反应温度低和产品易分离等特点.     

Stereoselective total synthesis of (−)-pyrenophorol

An efficient stereoselective total synthesis of (−)-pyrenophorol 1 is described. The key steps involved in this synthesis are hydrolytic kinetic resolution (HKR), MacMillan α-hydroxylation, Horner-Wadsworth-Emmons (HWE) reaction, and Mitsunobu cyclization.     

A Facile Synthesis of 3,4-Diamino-2,5-Diacylthieno[2,3-b]Thiophenes from Disodium(Dimercaptomethylene)Malononitrile and α-Halo Ketones

Various kinds of α-halo ketones readily reacted with disodium (dimercaptomethylene)malononitrile to give the corresponding 34-diamino-2,5-diacylthieno-[2,3-b]thiophenes in good to excellent yields. The reaction was successfully extended to the synthesis of a thienothiophene derivative having two sydnone rings by using the 4-(bromoacetyl)sydnone.     

Studies of Intramolecular Cyclization of 4-Arylpyridines. II Syntheses of Condensed Tricyclic Pyridines

A convenient method for the synthesis of condensed tricyclic pyridines using intramolecular cyclization of 4-arylpyridines is reported. The tricyclic compounds, 2-azafluorenone (9), 2-azafluorenone (10), 2-azafluorenol (11), lactones 12 and 13, and anhydride 14 have been prepared.     

New strategies in the synthesis of regioselectively trifluoromethyl- and trifluoromethoxy-substituted arenes as building blocks for biologically active molecules

Regioisomerically pure trifluoromethyl- and trifluoromethoxy-substituted aromatic and heteroaromatic aldehydes and carboxylic acids are valuable building blocks for the synthesis of biologically active molecules. They have been prepared by employing modern organometallic methods. On this basis, a novel access to 2,3-dihydro-5-(trifluoromethoxy)indole was developed which represents an intriguing example of how organometallic and radical chemistry can fecundate each other.