502462-00-2Relevant academic research and scientific papers
Bromine-magnesium-exchange as a general tool for the preparation of polyfunctional aryl and heteroaryl magnesium-reagents
Abarbri, Mohamed,Dehmel, Florian,Knochel, Paul
, p. 7449 - 7453 (1999)
The scope of the Br-Mg-exchange reaction for the preparation of polyfunctional aryl and heteroaryl magnesium reagents has been studied. Various functional groups (ester, cyano, bromide) were tolerated in the exchange reaction allowing the preparation of polyfunctional Mg-reagents. Several dibromo- or tribromoheterocycles undergo a chemoselective mono-Br-Mg exchange leading to highly functionalized heterocycles.
Cobalt-Catalyzed Cross-Coupling of Grignards with Allylic and Vinylic Bromides: Use of Sarcosine as a Natural Ligand
Frlan, Rok,Sova, Matej,Gobec, Stanislav,Stavber, Gaj,?asar, Zdenko
, p. 7803 - 7809 (2015/08/18)
Sarcosine was discovered to be an excellent ligand for cobalt-catalyzed carbon-carbon cross-coupling of Grignard reagents with allylic and vinylic bromides. The Co(II)/sarcosine catalytic system is shown to perform efficiently when phenyl and benzyl Grignards are coupled with alkenyl bromides. Notably, previously unachievable Co-catalyzed coupling of allylic bromides with Grignards to linearly coupled α-products was also realized with Co(II)/sarcosine catalyst. This method was used for efficient preparation of the key intermediate in an alternative synthesis of the antihyperglycemic drug sitagliptin.
SITAGLIPTIN INTERMEDIATE COMPOUNDS, PREPARATION METHODS AND USES THEREOF
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Paragraph 0027; 0061, (2013/03/26)
Sitagliptin intermediate compounds of formula (f) and methods of preparation and use thereof are disclosed. Compounds of formula (f) are prepared by the following steps: compounds of formula (a) are subjected to electrophilic reaction with benzyl halides to form compounds of formula (b), which then react with compounds of formula (i) to form novel compounds of formula (e). Gignard agents formed from 2,4,5-trifluoro brmobenzene and magnesium metal react with compounds of formula (e) to afford compounds of formula (f), which are novel intermediates for the preparation of Sitagliptin intermediates of formula (g). Compounds of formula (f) are subjected to reduction by Pd/C, debenzylation, substitution of protecting group to form compounds of formula (g). Compounds of formula (a), (b), (i), (e), (f), and (g) have the following structures, in which R is protecting group of carboxyl and R2 is (substituted) hydrocarbyl.
SITAGLIPTIN INTERMEDIATE COMPOUNDS, PREPARATION METHODS AND USES THEREOF
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Paragraph 0029, (2013/03/26)
The invention relates to Sitagliptin intermediate compounds of formula (f), preparation methods and uses thereof. The compound of formula (f) are prepared by the following steps: compounds of formula (a) are subjected to electrophilic reaction with benzyl halides to form compounds of formula (b), which then react with compounds of formula (i) to form novel compounds of formula (e); Gignard agents formed from 2,4,5-trifluoro bromobenzene and magnesium metal react with compounds of formula (e) to afford compounds of formula (f), which are novel intermediate compounds for the preparation of Sitagliptin intermediates of formula (g). The compound of formula (f) was subjected to reduction by Pd/C, debenzylation, substitution of protecting group to form the compounds of formula (g). The mentioned compounds have the following structures, wherein, R is the protecting group of carboxyl, R2 is (substituted) hydrocarbyl.
METHOD FOR PREPARING DIPEPTIDYL PEPTIDASE-IV INHIBITOR AND INTERMEDIATE
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Page/Page column 7, (2012/02/01)
The present invention relates to an improved method for preparing dipeptidyl peptidase-IV inhibitor and intermediate. The present invention is able to reduce preparation costs by using low cost reagents on reaction and is able to be used in mass production by improving yield.
The synthesis of a chiral β-amino acid derivative by the Grignard reaction of an aspartic acid equivalent
Liu, Feng,Yu, Wansheng,Ou, Wenhua,Xu, Xiaojiong,Ruan, Libo,Wang, Xiaoke,Li, Yiming,Peng, Xijiang,Tao, Xiaohu,Mao, Jun,Wan, Jiaomei,Pan, Xianhua
experimental part, p. 517 - 519 (2010/12/25)
A novel synthetic route to chiral β-amino acid derivative has been developed by a Grignard reaction of 2,4,5-trifluo- rophenyl magnesium bromide with the Weinreb amide derivative of L-aspartic acid. The aspartic equivalent was synthesised from L-aspartic
