Substituted 2H-pyran-2,6(3H)-dione derivatives useful in the treatment of allergic conditions are prepared by reaction of 3,5-diacetyl-4,6-dihydroxy-2H-pyran-2-one with an appropriate aniline.
FRANDSEN E. G., TETRAHEDRON, 1978, 34, NO 14, 2175-2178
作者:FRANDSEN E. G.
DOI:——
日期:——
PROCESS FOR THE PREPARATION OF PYRIDO [
2-1-A]
ISOQUINOLINE DERIVATIVES BY CATALYTIC ASYMMETRIC HYDROGENATION OF AN ENAMINE
申请人:Abrecht Stefan
公开号:US20080076925A1
公开(公告)日:2008-03-27
The invention relates to a process for the preparation of pyrido[2,1-
a
] isoquinoline derivatives of the formula
wherein R
2
, R
3
and R
4
are as defined in the specification, comprising the steps of a) catalytic asymmetric hydrogenation of an enamine of the formula
wherein R
1
is lower alkyl, in the presence of a transition metal catalyst containing a chiral diphosphane ligand, b) introduction of an amino protecting group Prot and c) amidation of the ester to form an amide of formula
wherein R
2
, R
3
, R
4
and Prot are as defined in the specification.
PROCESS FOR THE PREPARATION OF PYRIDO [2,1-a] ISOQUINOLINE DERIVATIVES COMPRISING OPTICAL RESOLUTION OF AN ENAMINE
申请人:Abrecht Stefan
公开号:US20080071087A1
公开(公告)日:2008-03-20
This invention relates to a process for the preparation of pyrido[2,1-a]isoquinoline derivatives of the formula
wherein R
1
, R
2
, R
3
and R
4
are defined in the specification, comprising the optical resolution of an enamine of the formula
wherein R
1
is lower alkyl, in the presence of an optical active resolving agent to form an (S)-enamine salt of the formula
wherein RCO
2
−
is the conjugate base of the resolving agent.