98167-06-7Relevant articles and documents
Chemo- and Enantioselective Hydrogenation of α-Formyl Enamides: An Efficient Access to Chiral α-Amido Aldehydes
Zhang, Jian,Jia, Jia,Zeng, Xincheng,Wang, Yuanhao,Zhang, Zhenfeng,Gridnev, Ilya D.,Zhang, Wanbin
, p. 11505 - 11512 (2019/07/17)
In order to effectively synthesize chiral α-amino aldehydes, which have a wide range of potential applications in organic synthesis and medicinal chemistry, a highly chemo- and enantioselective hydrogenation of α-formyl enamides has been developed, catalyzed by a rhodium complex of a P-stereogenic bisphosphine ligand. Under different hydrogen pressures, the chiral α-amido aldehydes and β-amido alcohols were obtained in high yields (97–99 %) and with excellent chemo- and enantioselectivities (up to >99.9 % ee). The hydrogenation can be carried out on a gram scale and with a high substrate/catalyst ratio (up to 20 000 S/C), and the hydrogenated products were further converted into several important chiral products. Computations of the catalytic cycle gave a clear description for the R/S pathways, provided a reasonable explanation for the enantioselectivity, and revealed several other specific features.
Resolution of Racemic Organic Acids with (1S, 4S)-4[3,4-Dichlorophenyl]-1,2,3,4-Tetrahydro-N-Methyl-1-Naphthaloneamine
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Page/Page column 3, (2009/10/18)
The present invention relates to novel chiral resolving agents and a process for resolution of racemic organic acids and their derivatives of the formula (+, ?)—R1R2CHCOOR3 with Cis-(1S,4S)-4[3,4-dichlorophenyl]-1,2,3,4-tetrahydro-N-methyl-1-naphthaloneamine and its Cis-(1R,4R)-isomer as well as Trans-(1S,4R)-4[3,4-dichlorophenyl]-1,2,3,4-tetrahydro-N-methyl-1-naphthaloneamine and its Trans-(1R,4S)-isomer.
PROCESS AND PRODUCT
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Page 7; 22; scheme, (2010/02/09)
A process of preparing perindopril of formula (I), or a pharmaceutically acceptable salt thereof which process comprises protecting a compound of formula (II) where R denotes a hydrogen atom, in the presence of benzene sulphonic acid as a catalyst, to obtain the benzene sulphonic acid salt of an ester of formula (III) where Rl is a carboxyl protecting group and reacting said ester of formula (III) with N-[(S)-1-carbethoxybutyl]-(S)-alanine to obtain a compound of formula (IV) where Rl is as defined above; and deprotecting a compound of formula (IV) to yield perindopril of formula (I), or a pharmaceutically acceptable salt thereof. There is also provided by the present invention the benzene sulphonic acid salt of an ester of formula (III), and perindopril or a pharmaceutically acceptable salt thereof prepared by the above process.
