A method for purification of a biphenol tetraacid composition includes contacting the biphenol tetraacid composition with a solvent including a C1-6 alcohol to form a slurry and isolating the purified biphenol tetraacid from the slurry. The biphenol tetraacid composition includes a biphenol tetraacid and a biphenol. A purified biphenol tetraacid composition is also described.

The present invention relates to a method for preparing 2-(2,5-difluorophenyl)-3-carboxy-7-chloro-(4H)-4-benzopyranone represented by formula 1 below, a novel intermediate used therein, and a method for preparing the same. Specifically, an object of the present invention is to provide a novel preparation method, in which the compound of formula 1 below can be efficiently and economically synthesized and can be mass-produced in a high yield.

##STR00001##

The present invention relates to a method for preparing 2-(2,5-difluorophenyl)-3-carboxy-7-chloro-(4H)-4-benzopyranone represented by formula 1 below, a novel intermediate used therein, and a method for preparing the same. Specifically, an object of the present invention is to provide a novel preparation method, in which the compound of formula 1 below can be efficiently and economically synthesized and can be mass-produced in a high yield.

##STR00001##

Methods are provided for modulating MRGPR X4 generally, or for treating a MRGPR X4 dependent condition more specifically, by contacting the MRGPR X4 or administering to a subject in need thereof, respectively, an effective amount of a compound having the structure of Formula (I): ##STR00001##
or a pharmaceutically acceptable isomer, racemate, hydrate, solvate, isotope, or salt thereof, wherein n, x, A, Q.sub.1, Q.sub.2, Z, R, R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are as defined herein. Pharmaceutical compositions containing such compounds, as well as to compounds themselves, are also provided.

The invention relates to pyridone amide compounds of formula I and I′ or pharmaceutically acceptable salts thereof, useful as inhibitors of sodium channels: ##STR00001## The invention also provides pharmaceutically acceptable compositions comprising the compounds of the invention and methods of using the compositions in the treatment of various disorders, including pain.

Homochiral metal organic framework (MOF) selected from a group consisting of (S.sub.p)-P5A-MOF-1 and (R.sub.p)-P5A-MOF-1 is provided. The homochiral MOFs are prepared from pure enantiomer struts of formula (I): ##STR00001##
The homochiral MOFs are suitable for separation of enantiomers from racemic mixtures.

Homochiral metal organic framework (MOF) selected from a group consisting of (S.sub.p)-P5A-MOF-1 and (R.sub.p)-P5A-MOF-1 is provided. The homochiral MOFs are prepared from pure enantiomer struts of formula (I): ##STR00001##
The homochiral MOFs are suitable for separation of enantiomers from racemic mixtures.

Homochiral metal organic framework (MOF) selected from a group consisting of (S.sub.p)-P5A-MOF-1 and (R.sub.p)-P5A-MOF-1 is provided. The homochiral MOFs are prepared from pure enantiomer struts of formula (I): ##STR00001##
The homochiral MOFs are suitable for separation of enantiomers from racemic mixtures.

A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a sieve tray extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent using a sieve tray extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.