摘要:
A (+)-stereoisomer of formula (I), wherein X is H or F; or a salt thereof; which is useful: as an anesthetic; for inducing or maintaining general anesthesia; for promoting sedation; for promoting an antiemetic effect; for treatment of nausea or vomiting; or for treatment of a migraine.
摘要:
A catalytic process for the preparation of optically active compounds and their conversion thereafter to desired drag substances. In particular, the process relates to the preparation of (S)-3-(1-Dimethylamino-ethyl)-phenol using asymmetric catalytic reduction and transfer hydrogenation, thereby providing an improved route to forming drug substances such as rivastigimine and rivastigimine hydrogen tartrate.
摘要:
A process for preparing 2,2-bis(4-hydroxyphenyl)propane (p,p-bisphenol-A) from2,4,4-trimethyl-2-(4-hydroxyphenyl)chroman (chroman 1.5) is disclosed. Phenol andchroman 1.5 are contacted over an acidic ion exchange resin at a given temperature for agiven period of time. The process results in improved quality of p,p-bisphenol-A, betterperformance of catalyst, improved raw material usage, and reduced waste.
摘要:
Process for the preparation of hydroxytyrosol, characterized by reacting 4- chloroacetyl-catechol with a metal formate and formic acid in an aqueous solvent optionally containing a lower alkanol and catalytically hydrogenating the 4- hydroxyacetyl-catechol obtained in the presence of a precious metal, preferably on a carrier.
摘要:
A process for the preparation of a compound of formula (I) wherein R is a hydrogen or a C1-6 alkyl group which is straight chain, branched or cyclic, with or without an oxygen, nitrogen or sulphur heteroatom anywhere in the chain or ring by reacting a compound of formula (II) with a source of hydrogen selected from either hydrogen or water in the presence of a mixture of at least two catalysts selected from nickel, raney nickel, and palladium, at a pH below 7.0 in a solvent medium comprising an alcohol having a carbon chain length of up to 3.
摘要:
The present invention relates to a method for deuteration of a compound having an aromatic ring, using an activated catalyst, and the method comprises reacting a compound having an aromatic ring with heavy hydrogen source in the presence of an activated catalyst selected from a platinum catalyst, a rhodium catalyst, a ruthenium catalyst, a nickel catalyst and a cobalt catalyst.
摘要:
Improved oxidation methods are provided wherein a reaction mixture comprising a substrate to be oxidized (e.g., phenols, alkenes) and an oxidation catalyst (typically dispersed in an organic solvent system) is supplemented with a compressed gas which expands the reaction mixture, thus accelerating the oxidation reaction. In preferred practice pressurized subcritical or supercritical carbon dioxide is used as the expanding gas, which is introduced into the reaction mixture together with an oxidizing agent. The inventive methods improve the substrate conversion and product selectivity by increasing the solubility of the oxidizing agent in the reaction mixture.