To provide a chiral reagent or a salt thereof.

The chiral reagent has following chemical formula (I). In the formula (I), G.sup.1 and G.sup.2 are independently a hydrogen atom, a nitro group (—NO.sub.2), a halogen atom, a cyano group (—CN), a group of formula (II) or (III), or both G.sup.1 and G.sup.2 taken together to form a group of formula (IV).

##STR00001##

To provide a chiral reagent or a salt thereof.

The chiral reagent has following chemical formula (I). In the formula (I), G.sup.1 and G.sup.2 are independently a hydrogen atom, a nitro group (—NO.sub.2), a halogen atom, a cyano group (—CN), a group of formula (II) or (III), or both G.sup.1 and G.sup.2 taken together to form a group of formula (IV).

##STR00001##

The present invention provides a process for preparing a compound represented by formula (VII), which comprises reacting a compound represented by formula (VI) with a malonic acid derivative in the presence of a base and an asymmetric catalyst in a two layer solvent system of hydrophobic solvent and water.

##STR00001##

(wherein R.sup.2 and R.sup.3 each independently represents a protecting group for carboxyl group),

The present invention provides a process for preparing a compound represented by formula (VII), which comprises reacting a compound represented by formula (VI) with a malonic acid derivative in the presence of a base and an asymmetric catalyst in a two layer solvent system of hydrophobic solvent and water.

##STR00001##

(wherein R.sup.2 and R.sup.3 each independently represents a protecting group for carboxyl group),

Provided is a preparation method for brivaracetam. The method has a synthetic route as shown below. The preparation method for the brivaracetam is simple, economical, environmentally friendly and suitable for industrialization:

##STR00001##

A process for performing a continuous gas/liquid biphasic high-pressure reaction, wherein a gas and a liquid are introduced into a backmixed zone of a reactor and in the backmixed zone the gas is dispersed in the liquid by stirring, injection of gas and/or a liquid jet, a reaction mixture consecutively traverses the backmixed zone and a zone of limited backmixing, and a liquid reaction product is withdrawn at a reaction product outlet of the zone of limited backmixing, wherein the reactor comprises: an interior formed by a cylindrical vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by means of internals into the backmixed zone, the zone of limited backmixing and a cavity, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a third internal element which in the interior extends in the longitudinal direction of the reactor and is open at the bottom, wherein the third internal element forms the cavity in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume. The reaction volume of the reactor used in the process can be reversibly reduced in simple fashion. The invention further relates to a process for adapting the reaction volume of a reactor suitable for performing a gas/liquid biphasic high-pressure reaction having an outlet for a liquid reaction product in which an internal element is arranged so as to form a cavity open at the bottom in which gas bubbles collect and do not escape upwards, thus preventing the volume of the cavity from being occupied by liquid and reducing the reaction volume.

Chiral acetyl-protected aminoethyl quinoline (APAQ), pyridine and imazoline ligands are disclosed that enable Pd (II)-catalyzed enantioselective arylation or heteroarylation of ubiquitous prochiral β-methylene C—H bonds of aliphatic amides offers an alternative disconnection for constructing β-chiral centers. Systematic tuning of the ligand structure reveals that a six-membered instead of a five-membered chelation of these types of ligands with the Pd(II) is important for accelerating the C(sp.sup.3)-H activation thereby achieving enantioselectivity for quinoline and pyridine ligands.

Chiral acetyl-protected aminoethyl quinoline (APAQ), pyridine and imazoline ligands are disclosed that enable Pd (II)-catalyzed enantioselective arylation or heteroarylation of ubiquitous prochiral β-methylene C—H bonds of aliphatic amides offers an alternative disconnection for constructing β-chiral centers. Systematic tuning of the ligand structure reveals that a six-membered instead of a five-membered chelation of these types of ligands with the Pd(II) is important for accelerating the C(sp.sup.3)-H activation thereby achieving enantioselectivity for quinoline and pyridine ligands.

A field of asymmetric catalytic synthesis, and in particular a preparation method for a high optical indoxacarb intermediate includes reacting 5-chloro-2-methoxycarbonyl-1-indanone ester (or indanone ester for short) with an oxidizing agent in the presence of a chiral Zr-salen polymer to obtain an indoxacarb intermediate (2S)-5-chloro-2,3-dihydro-2-hydroxy-1-oxo-1H-indole-2-carboxylic acid methyl ester. The yield is stabilized between 86% and 90%, and the S-enantiomer content is up to 99%. Such catalyst can replace catalysts such as cinchonine, and greatly increase the content of the effective S-enantiomer of the indoxacarb, so that the content of the hydroxyl intermediate S-enantiomer of the indoxacarb is raised from 75% to 99% or more. In addition, the chiral Zr-salen polymer catalyst is recycled without retreatment, and can be recycled at least 5 times or more, greatly reducing the production cost and laying a foundation for the industrial production of high quality indoxacarb.

Described herein are methods of inducing an immune response directed towards preventing or reducing the risk of a human immunodeficiency virus (HIV) infection in a mammalian subject. The subject is administered an effective amount of a composition containing IgM antibodies directed to an epitope of an envelope protein of the HIV virus. Also disclosed here are vaccine compositions comprising IgM antibodies directed to one or more epitopes of one or more human immunodeficiency virus envelope proteins. Also disclosed are recombinant immunoglobulin M compositions containing a Fcγ fragment of an immunoglobulin G.