The present invention refers to a new process for the synthesis of (9,10)-pregn-4-ene-3,20-dione, commonly known as retroprogesterone, having the formula (1) shown below.

##STR00001##

The present invention refers to a new process for the synthesis of (9,10)-pregn-4-ene-3,20-dione, commonly known as retroprogesterone, having the formula (1) shown below.

##STR00001##

The invention provides an improved process for preparing Ethacrynic acid of formula I, including the steps of: (a) reacting 4-butyryl-2,3-dichloro-phenoxy acetic acid of formula II with dimethylamine or its salt to obtain [2,3-dichloro-4-(2-dimethylaminomethylbutyryl)phenoxy] acetic acid of formula III or its salt; (b) hydrolyzing [2,3-dichloro-4-(2-dimethylaminomethylbutyryl)phenoxy] acetic acid hydrochloride of formula III obtained in step a) with t-butyl amine to obtain t-butyl amine salt of Ethacrynic acid; (c) acidifying the t-butyl amine salt of Ethacrynic acid formed in step b) to obtain Ethacrynic acid of formula I; and (d) optionally purifying the obtained Ethacrynic acid with a solvent mixture of alkyl acetate and hydrocarbon solvent. The invention also provides crystalline t-butylamine salt of Ethacrynic acid and process thereof. Also provide compound Ethacrynic acid having a purity of greater than or equal to 99% and a composition including the compound.

The invention provides an improved process for preparing Ethacrynic acid of formula I, including the steps of: (a) reacting 4-butyryl-2,3-dichloro-phenoxy acetic acid of formula II with dimethylamine or its salt to obtain [2,3-dichloro-4-(2-dimethylaminomethylbutyryl)phenoxy] acetic acid of formula III or its salt; (b) hydrolyzing [2,3-dichloro-4-(2-dimethylaminomethylbutyryl)phenoxy] acetic acid hydrochloride of formula III obtained in step a) with t-butyl amine to obtain t-butyl amine salt of Ethacrynic acid; (c) acidifying the t-butyl amine salt of Ethacrynic acid formed in step b) to obtain Ethacrynic acid of formula I; and (d) optionally purifying the obtained Ethacrynic acid with a solvent mixture of alkyl acetate and hydrocarbon solvent. The invention also provides crystalline t-butylamine salt of Ethacrynic acid and process thereof. Also provide compound Ethacrynic acid having a purity of greater than or equal to 99% and a composition including the compound.

A method of preparing succinic acid; the method comprising contacting glucose with an oxidizing catalyst under conditions to produce a first oxidized product; converting the first oxidized product to an aldehyde; and contacting the aldehyde with an acid catalyst under conditions suitable for the formation of succinic acid.

A method of preparing succinic acid; the method comprising contacting glucose with an oxidizing catalyst under conditions to produce a first oxidized product; converting the first oxidized product to an aldehyde; and contacting the aldehyde with an acid catalyst under conditions suitable for the formation of succinic acid.

A process for the specific isotopic labeling of an amino acid selected from Valine (Val), Leucine (Leu), and Isoleucine (Ile), in proteins and biomolecular assemblies by introducing, in a medium containing bacteria overexpressing a protein, an acetolactate derivative of Formula I of the application.

A process for the specific isotopic labeling of an amino acid selected from Valine (Val), Leucine (Leu), and Isoleucine (Ile), in proteins and biomolecular assemblies by introducing, in a medium containing bacteria overexpressing a protein, an acetolactate derivative of Formula I of the application.

The invention provides an improved process for preparing Ethacrynic acid of formula I, including the steps of: (a) reacting 4-butyryl-2,3-dichloro-phenoxy acetic acid of formula II with dimethylamine or its salt to obtain [2,3-dichloro-4-[2-dimethylaminomethyl butyryl phenoxy acetic acid of formula III or its salt; (b) hydrolysing [2,3-dichloro-4-[2-dimethylaminomethyl butyryl phenoxy acetic acid hydrochloride of formula III obtained in step a) with t-butyl amine to obtain t-butyl amine salt of Ethacrynic acid; (c) acidifying the t-butyl amine salt of Ethacrynic acid formed in step b) to obtain Ethacrynic acid of formula I; and(d) optionally purifying the obtained Ethacrynic acid with a solvent mixture of alkyl acetate and hydrocarbon solvent. The invention also provides crystalline t-butylamine salt of Ethacrynic acid and process thereof. Also provide compound Ethacrynic acid having a purity of greater than or equal to 99% and a composition including the compound.

The invention provides an improved process for preparing Ethacrynic acid of formula I, including the steps of: (a) reacting 4-butyryl-2,3-dichloro-phenoxy acetic acid of formula II with dimethylamine or its salt to obtain [2,3-dichloro-4-[2-dimethylaminomethyl butyryl phenoxy acetic acid of formula III or its salt; (b) hydrolysing [2,3-dichloro-4-[2-dimethylaminomethyl butyryl phenoxy acetic acid hydrochloride of formula III obtained in step a) with t-butyl amine to obtain t-butyl amine salt of Ethacrynic acid; (c) acidifying the t-butyl amine salt of Ethacrynic acid formed in step b) to obtain Ethacrynic acid of formula I; and(d) optionally purifying the obtained Ethacrynic acid with a solvent mixture of alkyl acetate and hydrocarbon solvent. The invention also provides crystalline t-butylamine salt of Ethacrynic acid and process thereof. Also provide compound Ethacrynic acid having a purity of greater than or equal to 99% and a composition including the compound.