98717-16-9Relevant articles and documents
Direct Catalytic N-Alkylation of α-Amino Acid Esters and Amides Using Alcohols with High Retention of Stereochemistry
Yan, Tao,Feringa, Ben L.,Barta, Katalin
, p. 2303 - 2307 (2021/05/11)
The direct functionalization of naturally abundant chiral scaffolds such as α-amino acid esters or amides with widely abundant alcohols, without any racemization, is a demanding transformation that is of central importance for the synthesis of bio-active compounds. Herein a robust and general method was developed for the direct N-alkylation of α-amino acid esters and amides with alcohols. This powerful ruthenium-catalyzed methodology is atom-economic, base-free, and allowed for excellent retention of stereochemical integrity. The use of diphenylphosphate as additive was crucial for significantly enhancing reactivity and product selectivity. Notably, the only by-product was water and both substrates could be potentially derived from renewable resources.
A convenient and highly enantioselective synthesis of (S)-2-pipecolic acid: an efficient access to caine anesthetics
Yang, Yuyan,Li, Hua,You, Zhonglin,Zhang, Xingxian
, p. 3084 - 3089 (2021/08/12)
A novel and enantioselective synthesis of (S)-2-pipecolic acid (5) has been achieved from Oppolzer’s sultam (1) and ethyl N-(diphenylmethylene)glycinate (2) as readily available starting materials. The highly stereoselective alkylation of chiral glycine intermediate (3) with 1,4-dibromobutane afforded the key backbone of (S)-2-pipecolic acid (5) in one-step that was utilized into the preparation of the local anesthetics mepivacaine, ropivacaine and bupivacaine.
Preparation method of ropivacaine hydrochloride
-
, (2017/11/29)
The invention discloses a preparation method of ropivacaine hydrochloride. The preparation method comprises steps as follows: (1) preparation of an intermediate (I), (2) preparation of an intermediate (II), (3) preparation of a crude product and (4) refin