A New Synthetic Route for 2,4-Dibromo-5-fluorobenzoic Acid

Fluoroquinolonesareeffectivemedicinesagainstbacteria,evenagainsttumor.Overtenexcellentfluoroquinol0nemedicineshavebeen0nthemarket.Duet0thehigherselectivity,yieldatbrondnationof3-flu0rotoluenethanchlorination,and0theradvantages'-',2,4-dibromo-5-flu0r0benzoicacidhasreplaced2,4-dichloro-5-fluor0-benzoicacidandbecomethekeystartingmaterialofpreparingfluoroquinoIonemedicines'.S0itisofgreatsignificancetofindaneffectivesyntheticpathfor2,4-dibromo-5-fluor0benz0icacid.Therehavebeenproposedtwomethodsf0r…     

邻氯苯甲腈的新合成法

以邻氯溴苯为起始原料,选用K4[Fe(CN)6]为氰基化试剂,Pd/C催化反应制得邻氯苯甲腈。 考察了温度、碱、催化剂的用量和原料比等对反应的影响,确定了较佳反应条件。 邻氯溴苯转化率达98.5%,产物邻氯苯甲腈得率95.1%。     

A New Synthetic Route to 5-Isoxazolamines

5-Isoxaz0lamineshavebeenusedasintermediatesforthesynthesis0fderivatives0fantihistaminic,analgetic,antibacterial,insecticidal,herbicidalandfungicidalactivity'.Usuallytheyaresynthesizedbytheintramolecularcondensation0fhydr0xylamineand0-nitrilegr0up'.Otherapproaches,suchasreductivecyclizati0nofZ-a-cyano-6-nitroethylenesandIithiumaIuminumhydridereduction0f3-cyanooxazoleshaveals0beenrepoFted'-'.HerewerepoFtanewsyntheticrouteofthesecompounds.Ohn0andNaruse7havereportedthatthereactionof2-chlorocycl…     

磷酸特地唑胺的合成新方法

以(5R)-3-(4-溴-3-氟苯基)-5-羟甲基噁唑烷-2-酮为起始原料,在[PdCl₂(dppf)]·CH₂Cl₂催化下与联硼酸频那醇酯反应得到硼化物,继而与5-溴-2-(2-甲基-2H-四唑-5-基)吡啶进行Suzuki反应得到特地唑胺,收率82.9%。 分别考察了催化体系对硼化反应和Suzuki反应的影响,确定了较佳的反应条件。 特地唑胺与二苄基N,N-二异丙基亚磷酰胺反应得到二苄基保护的磷酸特地唑胺,随后经Pd/C脱苄得到磷酸特地唑胺,总收率66.2%。     

A New Synthetic Route to Selected Indenones

Indenones are useful intermediates in the synthesis of several natural products, e.g. gibberellins (1) and steroid hormones with a C-nor-D-home system (2). Despite the nernerous methods for indenone synthesized, or the yields was much lower as mentioned in earlier reports (1)(4). One of the difficulties of the usual methods is the required electrophilic cyclization meta to a methoxyl substiruent. House (5) deals with these difficulties in more detail. In our method the synthesis of 6-methoxyinde-nones is effected by substitution dara to methoxyl function.     

4-溴代苯酐的合成新方法

将4-硝基邻苯二甲酰亚甲胺（4-NPI）用铁粉还原为4-氨基邻苯二甲酰亚甲胺 ，再在氢氧化钠水溶液中水解成4-氨基邻苯二甲酸钠。4-氨基邻苯二甲酸钠在氢溴 酸中经Sandmeyer反应合成4-溴代苯酐。产品纯度高，是合成4-溴代苯酐的一个比较 理想的方法。     

还原热解催化合成金刚石新法

ＳｙｎｔｈｅｔｉｃＤｉａｍｏｎｄｆｒｏｍａＮｏｖｅｌＲｅｄｕｃｔｉｏｎ┐Ｐｙｒｏｌｙｓｉｓ┐ＣａｔａｌｙｓｔＲｏｕｔｅ１．论文名称ＡＲｅｄｕｃｔｉｏｎ－Ｐｙｒｏｌｙｓｉｓ－ＣａｔａｌｙｓｔＳｙｎｔｈｅｓｉｓｏｆＤｉａｍｏｎｄ２．发表刊物Ｓｃｉｅｎｃｅ...     

含硫—硫键的新型苯胺类化合物的合成

通过一条新的合成路线得到了一个已知化合物5-氨基-1,4-二氢苯唑并[d]-1',2'-二硫因(1). 同时成功地合成了一个新的类似化合物9-氨基-1,2,3,4,5,6,7,8-八氢-2,3,6,7-四硫代蒽(2). 目标化合物及其中间体的结构经¹H, ¹³C NMR, MS, IR确证, X单晶衍射测定了化合物9-硝基-1,2,3,4,5,6,7,8-八氢-2,3,6,7-四硫代蒽(10)的结构.     

New Synthetic Route to Polyhedral Organylsilsesquioxanes

Hydrosilation of methylenecyclohexane and hex-1-ene by octa(hydridosilsesquioxane) catalysed by hexachloroplatinic acid is a new route to polyhedral organylsilsesquioxanes. Quantitative yield of octa(cyclohexylmethylsilsesquioxane) is reached. This reaction opens a vast field of yet unknown polyhedral silsesquioxanes.     

New Synthetic Route to Pummerer's Ketone

Pummerer's ketone 1 is obtained with an overall yield of 55 % by the following sequence: Claisen rearrangement of an arylcyclohexylether 3; allylic oxidation of the methylcycloalkylphenolic derivative 4b, then spontaneous cyclisation during demethylation to give 2. 1 is obtained by dehydrogenation of 2. NMR data agree with a cis stereochemistry at C_4a and C _9b.     

A New Synthetic Route for Preparation of 2-Chloro-6-fluoro-benzonitrile and 2-Chloro-6-fluorobenzoic Acid

An effective synthetic route for preparation of 2-chloro-6-fluorobenzonitrile, 2-chloro-6-fluorobenzamide and 2-chloro-6-fluorobenzoic acid has been described. It includes diazotization,fluorination, ammoxidation and hydrolysis reactions.     

一种合成3,5-二氨基吡啶及3,5-二甲氧羰基氨基吡啶的新路线

以3,5-二甲基吡啶为起始原料,经氧化、酰胺化,酰胺在不同的霍夫曼降解条件下合成3,5-二氨基吡啶及3,5-二甲氧羰基氨基吡啶,总收率分别为64%和68%。利用1H NMR、MS/MS、IR等方法对各化合物的结构进行了表征。讨论了氧化反应及霍夫曼降解反应的主要影响因素。反应均在常压下进行,反应条件温和,后处理简单,效率高。     

An Expeditious Synthetic Route to Carnosic Acid Type Diterpenes

2-Oxo-10-carboxy-8,11,13-podocarpatriene 7, a model for carnosic acid type diterpenes has been synthesized by an expeditious synthetic route.