描述了以蒽和吡啶为末端基团的联噻吩的合成。源自噻吩硼酸1和相应的溴吡啶2a、2b的3-和4-噻吩基吡啶3与2-(9-蒽基)-5-碘噻吩4偶联,得到异构的(9-蒽基)联噻吩吡啶5a、5b。为了在供电子蒽和联噻吩之间引入亚甲基间隔基,5-(2,2'-联噻吩)溴化镁7与2反应生成联噻吩吡啶9a、9b。9与9-羟甲基蒽反应得到3-和4-(9-蒽甲基)联噻吩吡啶11a、11b。通过与异构的吡啶甲醛14a、14b反应,通过亚甲基间隔基将吡啶连接到联噻吩上。然而,用NaBH3CN/ZnI2使生成的醇15a、15b去羟基化,得到了N-氰硼烷加合物16a、16b,通过在EtOH或6 N HCl中加热,将其转化为所需的3-和4-(联噻吩甲基)吡啶18a、18b。用CF3SO3Me在CH2Cl2或Et2O为溶剂中对吡啶5、9、11和18进行甲基化,得到高纯度的相应吡啶季盐6、12、13和19。
[EN] AN IMPROVED PROCESS TO SYNTHESIZE 5-(3-PYRIDYL)-2,2'-BITHIOPHENE(SENSITIZER) [FR] PROCÉDÉ AMÉLIORÉ DE SYNTHÈSE DE 5-(3-PYRIDYL)-2,2'-BITHIOPHÈNE (SENSIBILISATEUR)
[EN] IMPROVED PHOTOCHEMICAL SYNTHESIS OF VITAMIN D3 USING SENSITIZERS [FR] SYNTHÈSE PHOTOCHIMIQUE AMÉLIORÉE DE LA VITAMINE D3 À L'AIDE DE SENSIBILISATEURS
[EN] AN EFFICIENT METHOD FOR SYNTHESIS OF 5-(3-PYRIDYL)-2,2'-BITHIOPHENE(SENSITIZER)<br/>[FR] PROCÉDÉ EFFICACE POUR LA SYNTHÈSE DU 5-(3-PYRIDYL)-2,2'-BITHIOPHÈNE (SENSIBILISATEUR)
申请人:FERMENTA BIOTECH LTD
公开号:WO2021019558A1
公开(公告)日:2021-02-04
The present invention discloses an efficient process for synthesis of photosensitizer, 5-(3-pyridyl)-2,2'-bithiophene in high yield and purity.
本发明公开了一种高效合成光敏剂5-(3-吡啶基)-2,2'-双噻吩的高产率和高纯度工艺。
Palladium‐Catalysed Direct Monoarylation of Bithiophenyl Derivatives or Bis(thiophen‐2‐yl)methanone with Aryl Bromides
作者:Karima Si Larbi、Safia Djebbar、Henri Doucet
DOI:10.1002/ejic.201100294
日期:2011.8
Arylated bithiophenes, which are useful compounds due to their coordination and/or physical properties, can be easily prepared by palladium-catalysed C–H bond activation of heteroaromatics followed by arylation using electron-deficient aryl bromides. A variety of 5-arylated 2,2′-bithiophenyl derivatives have been prepared. Good yields were generally obtained by using the air-stable [PdCl(dppb)(C3H5)]
[EN] IMPROVED, COST EFFECTIVE PROCESS FOR SYNTHESIS OF VITAMIN D3 AND ITS ANALOGUE CALCIFEDIOL FROM ERGOSTEROL<br/>[FR] PROCÉDÉ ÉCONOMIQUE, AMÉLIORÉ, DE SYNTHÈSE DE VITAMINE D3 ET SON ANALOGUE CALCIFÉDIOL À PARTIR D'ERGOSTÉROL
申请人:FERMENTA BIOTECH LTD
公开号:WO2021005619A1
公开(公告)日:2021-01-14
Disclosed herein is an improved and efficient process for synthesis of vitamin D3 and its analogue Calcifediol from Ergosterol. Particularly, the present invention discloses the synthesis of key intermediate 3β-tert-Butyldimethylsilyloxy-22-hydroxy-23,24-bisnorchola-5,7-diene (5), and novel intermediate β-tert-Butyldimethylsilyloxy-22-iodo-23,24-bisnorchola-5,7-diene (9) by a simple and cost effective process. The industrially viable processes for preparation of said intermediate(s) results in providing provitamins with various side chains and the desired products in high yield.