65732-89-0Relevant articles and documents
Simple one-pot process for the bioresolution of tertiary amino ester protic ionic liquids using subtilisin
Brossat, Maude,Moody, Thomas S.,Taylor, Stephen J.C.,Wiffen, Jonathan W.
experimental part, p. 2112 - 2116 (2010/02/28)
An efficient hydrolase-catalyzed bioresolution of tertiary amino ester protic ionic liquids has been demonstrated. Protic ionic liquids have been prepared in one step from the corresponding tertiary amino alcohols by treatment with butyric anhydride. Afte
A practical chemoenzymatic process to access (R)-quinuclidin-3-ol on scale
Nomoto, Fumiki,Hirayama, Yoshihiko,Ikunaka, Masaya,Inoue, Toru,Otsuka, Koutaro
, p. 1871 - 1877 (2007/10/03)
(±)-3-Butyryloxyquinuclidinium butyrate 6 (2 M, 571 g/L), prepared from (±)-quinuclidin-3-ol 1 and butyric anhydride, undergoes enantioselective hydrolysis by an Aspergillus melleus protease {1.0% (w/v)} in water in the presence of Ca(OH)2 to keep the reaction at pH 7 and trap butyric acid that is introduced as part of (±)-6 and generated by the enzymatic hydrolysis. After a 24 h period, extraction with n-heptane provides (R)-quinuclidin-3-yl butyrate 5a, which, on methanolysis with Na2CO3, is converted into (R)-1, a common pharmacophore of neuromodulators acting on muscarinic receptors, in 96% ee and 42% overall yield from (±)-1. The unwanted antipode (S)-1, which is extracted into n-butanol and purified via its hydrochloride salt in 89% ee and 40% overall yield from (±)-1, can be racemized by the catalysis of Raney Co at 140°C under an atmosphere of H2 (5 kg/cm2) to regenerate (±)-1 in 97% yield.
