[EN] HIGH RELAXIVITY CONTRAST AGENTS AND STEREOSELECTIVE PREPARATION [FR] AGENTS DE CONTRASTE À HAUTE RELAXIVITÉ ET PRÉPARATION STÉRÉOSÉLECTIVE
摘要:
A compound has a structure according to formula IA or IB, or a salt or stereoisomer thereof: (IA) or (IB), where each R1independently is an aryl or aliphatic group having an sp2‑hybridized or sp‑hybridized carbon at its attachment point to the carbon atom alpha to nitrogen, and Ln is a lanthanide ion. The aryl or aliphatic group may be substituted or unsubstituted. The disclosed compounds may be useful as contrast agents, such as magnetic resonance imaging contrast agents. Some stereoisomers of the disclosed chelated compounds according to formula IB have a high relaxivity. In certain instances, the relaxivity is close to a theoretical maximum value for the chelate. A stereoselective synthesis for preparing the compounds is disclosed.
With hydrolysis of (R,S)-azolides in water-saturated methyl tert-butyl ether (MTBE) via Candida antarctica lipase B (CALB) as the model system, (R,S)-pyrazolides containing a leaving 3-, 4- or 3,4-substituted-pyrazole moiety are selected as the best substrates for preparing various optically pure carboxylic acids containing an α-chiral center. Great improvements of enzyme activity for the (R)-enantiomers
<i>N</i>-Benzoyl-<scp>L</scp>-Threonine-Isopropyl-Ester-Mediated Crystallization-Induced Dynamic Resolution of α-Bromo Arylacetates for the Asymmetric Synthesis of α-Thio and α-Oxy Arylacetates
作者:Kon Ji Park、Yelim Kim、Myung-su Lee、Yong Sun Park
DOI:10.1002/ejoc.201301539
日期:2014.3
N-Benzoyl-L-threonine-isopropyl-ester-mediatedcrystallization-induceddynamicresolution (CIDR) of configurationally labile α-bromoarylacetates has been investigated. The CIDR was successfully used for the asymmetric preparation of these compounds with up to 98:2 dr, under solution and solvent-free conditions. Subsequent nucleophilic substitution reactions with sulfur and oxygen nulceophiles gave
Dynamic kinetic resolution in the hydrolysis of an α-bromo ester
作者:Matthew M. Jones、Jonathan M. J. Williams
DOI:10.1039/a807232i
日期:——
Bromide can be employed to racemise an α-bromo ester more rapidly than the corresponding acid (carboxylate), and this rate difference has been employed as the basis of a dynamic kinetic resolution reaction.
溴化物可以比相应的酸(羧酸盐)更快地消旋化δ-溴酯,这种速率差异已被用作动态动力学解析反应的基础。
D2 ANTAGONISTS, METHODS OF SYNTHESIS AND METHODS OF USE
申请人:Luehr Gary W.
公开号:US20120010228A1
公开(公告)日:2012-01-12
Provided are D
2
or D
3
antagonist compounds and pharmaceutical compositions of formula I
and pharmaceutically acceptable salts thereof, or isomers thereof, wherein R
1
, R
2
and R
3
are as defined herein. The invention further comprises methods for making the compounds of the invention and methods for the treatment of conditions mediated by the dopamine D
2
or D
3
receptor from the compounds of the invention.
D2 antagonists, methods of synthesis and methods of use
申请人:Luehr Gary W.
公开号:US08691836B2
公开(公告)日:2014-04-08
Provided are D2 or D3 antagonist compounds and pharmaceutical compositions of formula I
and pharmaceutically acceptable salts thereof, or isomers thereof, wherein R1, R2 and R3 are as defined herein. The invention further comprises methods for making the compounds of the invention and methods for the treatment of conditions mediated by the dopamine D2 or D3 receptor from the compounds of the invention.