The invention relates to a new enantioselective process for producing useful intermediates for the manufacture of NEP inhibitors or prodrugs thereof, in particular NEP inhibitors comprising a -amino--biphenyl--methylalkanoic acid, or acid ester, backbone.

The present invention relates generally to compositions and methods for treating neurodegenerative diseases and disorders, particularly ophthalmic diseases and disorders. Provided herein are alkoxyl derivative compounds and pharmaceutical compositions comprising these compounds. The subject compositions are useful for treating and preventing ophthalmic diseases and disorders, including age-related macular degeneration (AMD) and Stargardt's Disease.

The present invention relates generally to compositions and methods for treating neurodegenerative diseases and disorders, particularly ophthalmic diseases and disorders. Provided herein are alkoxyl derivative compounds and pharmaceutical compositions comprising these compounds. The subject compositions are useful for treating and preventing ophthalmic diseases and disorders, including age-related macular degeneration (AMD) and Stargardt's Disease.

Methods for the synthesis of enantiopure (S)-methadone, (R)-methadone, (R,S)-methadone and related analogues starting from optically active or racemic N-substituted cyclic sulfamidates, or N-substituted aziridines with retention of stereochemical configuration. The methods avoid the formation of isomethadone-nitrile by-products observed under the previously reported conditions, namely the ring-opening reaction of the corresponding 1,1,2-trimethylaziridin-1-ium salt and the 2,2-diphenylacetonitrile anion, resulting in improved yields and facile purification operations.

Methods for the synthesis of enantiopure (S)-methadone, (R)-methadone, (R,S)-methadone and related analogues starting from optically active or racemic N-substituted cyclic sulfamidates, or N-substituted aziridines with retention of stereochemical configuration. The methods avoid the formation of isomethadone-nitrile by-products observed under the previously reported conditions, namely the ring-opening reaction of the corresponding 1,1,2-trimethylaziridin-1-ium salt and the 2,2-diphenylacetonitrile anion, resulting in improved yields and facile purification operations.

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.

The present invention relates generally to compositions and methods for treating neurodegenerative diseases and disorders, particularly ophthalmic diseases and disorders. Provided herein are alkoxyl derivative compounds and pharmaceutical compositions comprising these compounds. The subject compositions are useful for treating and preventing ophthalmic diseases and disorders, including age-related macular degeneration (AMD) and Stargardt's Disease.

The present invention relates generally to compositions and methods for treating neurodegenerative diseases and disorders, particularly ophthalmic diseases and disorders. Provided herein are alkoxyl derivative compounds and pharmaceutical compositions comprising these compounds. The subject compositions are useful for treating and preventing ophthalmic diseases and disorders, including age-related macular degeneration (AMD) and Stargardt's Disease.

Highly efficient methods for synthesis of levomethadone hydrochloride or dextromethadone hydrochloride are provided starting from D-alanine, or L-alanine, respectively, with retention of configuration. Methods for treating a subject are provided comprising administering a composition comprising an effective amount of levomethadone hydrochloride having not more than 10 ppm dextromethadone.