A highly enantioselective tandem Michael/ring‐closurereaction of α,β‐unsaturated pyrazoleamides and amidomalonates has been accomplished in the presence of a chiral N,N′‐dioxide–Yb(OTf)3 complex (Tf: trifluoromethanesulfonyl) to give various substituted chiral glutarimides with high yields and diastereo‐ and enantioselectivities. Moreover, this methodology could be used for gram‐scale manipulation
[EN] AN IMPROVED PROCESS FOR THE PREPARATION OF PAROXETINE AND ITS INTERMEDIATE<br/>[FR] PROCÉDÉ AMÉLIORÉ DE PRÉPARATION DE PAROXÉTINE ET DE SON INTERMÉDIAIRE
申请人:PIRAMAL ENTPR LTD
公开号:WO2017037662A1
公开(公告)日:2017-03-09
The present invention provides an improved process for the preparation of N-protected ((3S,4R)- 4-(4-fluorophenyl)piperidin-3-yl)methanol (compound (A)) and further its transformation to Paroxetine and its pharmaceutically acceptable salts. The process comprises reaction of compound (II) with amido-malonate compound (C) in the presence of a chiral catalyst and optionally a dehydrating agent to obtain compound (B); followed by reduction of (B) in the presence of a reducing agent to provide compound (A).
[EN] AN IMPROVED PROCESS FOR MINIMISING THE FORMATION OF DEHALOGENATED BYPRODUCTS<br/>[FR] PROCÉDÉ AMÉLIORÉ PERMETTANT DE RÉDUIRE AU MINIMUM LA FORMATION DE SOUS-PRODUITS DÉSHALOGÉNÉS
申请人:PIRAMAL ENTPR LTD
公开号:WO2015071831A1
公开(公告)日:2015-05-21
The present invention provides an improved process for preparation of organic compounds represented by Formula-Z; wherein effectively minimising the formation of dehalogenated by-products is achieved. In the process, the reduction is carried out using suitable reducing agent; more preferably Lithium Aluminium Hydride (LAH) in a solvent system, wherein at least one of the solvent is selected from halogenated solvents, which acts as co-solvent. The process of the present invention is useful for minimising of the formation of dehalogenated by-products during synthesis of various active pharmaceutical ingredients such as Paroxetine Hydrochloride, Cinacalcet, Eletriptan and Asenapine.
Process for preparing arylpiperidine carbinol intermediates and derivatives
申请人:——
公开号:US20010053862A1
公开(公告)日:2001-12-20
A process for the synthesis of arylpiperidine carbinol intermediates and derivatives is disclosed. A preferred process embodiment provides the synthesis of intermediate compounds of structural formula (I) and structural formula (II):
1
where X is halo, C
1
-C
10
alkoxy, C
1
-C
10
haloalkyl, or hydroxy; R
2
and R
3
are each C
1
-C
4
alkyl, and R
2
and R
3
are the same. The compound of structural formula (I) is made by condensing a corresponding cinnamonitrile with a corresponding diester malonate. The compound of structural formula (II) in the (±)-trans configuration is obtained by hydrogenating the compound of structural formula (I). The compounds of structural formula (I) and structural formula (II) are useful chemical intermediates for synthesizing 4-arylpiperidine-3-carbinols and their derivatives in (−)-trans configuration.
NOVEL REDUCTION COMPOSITIONS AND PROCESSES FOR MAKING THE SAME
申请人:——
公开号:US20010051729A1
公开(公告)日:2001-12-13
Novel reduction compositions are prepared from an active hydride, an additive, and a Lewis base in a hydrocarbon solvent. Such compositions can provide a superior reducing system for organic substrates.