An efficient process for the manufacture of carmegliptin
A short and high-yielding synthesis of carmegliptin (1) suitable for large-scale production is reported. The tricyclic core was assembled efficiently by a decarboxylative Mannich addition-Mannich cyclization sequence. Subsequent crystallization-induced dynamic resolution of enamine 7 using (S,S)-dibenzoyltartaric acid was followed by diastereoselective enamine reduction to give the fully functionalized tricyclic core with its three stereogenic centers. The C-3 nitrogen was introduced by Hofmann rearrangement of amide 28, and the resulting amine 10 was coupled with (S)-fluoromethyl lactone 31. Following cyclization to lactam 13 and amine deprotection, 1 was obtained in 27-31% overall yield with six isolated intermediates.
PROCESS FOR THE PREPARATION OF PYRIDO [ 2-1-A] ISOQUINOLINE DERIVATIVES BY CATALYTIC ASYMMETRIC HYDROGENATION OF AN ENAMINE
The invention relates to a process for the preparation of pyrido[2,1-a] isoquinoline derivatives of the formula wherein R2, R3and R4 are as defined in the specification, comprising the steps of a) catalytic asymmetric hydr
-
Page/Page column 12
(2008/06/13)
PROCESS FOR THE PREPARATION OF PYRIDO [2,1-a] ISOQUINOLINE DERIVATIVES COMPRISING OPTICAL RESOLUTION OF AN ENAMINE
This invention relates to a process for the preparation of pyrido[2,1-a]isoquinoline derivatives of the formula wherein R1, R2, R3 and R4 are defined in the specification, comprising the optical resolution of an
-
Page/Page column 10
(2008/06/13)
More Articles about upstream products of 1012065-72-3
Get Best Price for1012065-72-3Butanedioic acid, 2,3-bis(benzoyloxy)-, (2S,3S)-, compd. with ethyl (11bS)-2-amino-1,6,7,11b-tetrahydro-9,10-dimethoxy-4H-benzo[a]quinolizine-3-carboxylate (1:1)