A novel process for the preparation of L-threo-dihydroxyphenylserine (Droxidopa) is described. It comprises of enantioselective hydrolysis of racemic (DL)-threo-N-acetyl-3-(3,4-methylenedioxyphenyl)-serine using commercially available L-amino acylase from Aspergillus sp. (EC 3.5.1.14) in the presence of cobalt ions, to obtain (L)-threo-3-(3,4-methylenedioxyphenyl)-serine followed by dealkylation to obtain Droxidopa. Protecting the amino group of (L)-threo-3-(3,4-methylenedioxyphenyl)-serine using either benzyloxycarbonyl or phthaloyl group before dealkylation followed by deprotection of the amino group results in obtaining Droxidopa in high yields and purity.

A novel process for the preparation of L-threo-dihydroxyphenylserine (Droxidopa) is described. It comprises of enantioselective hydrolysis of racemic (DL)-threo-N-acetyl-3-(3,4-methylenedioxyphenyl)-serine using commercially available L-amino acylase from Aspergillus sp. (EC 3.5.1.14) in the presence of cobalt ions, to obtain (L)-threo-3-(3,4-methylenedioxyphenyl)-serine followed by dealkylation to obtain Droxidopa. Protecting the amino group of (L)-threo-3-(3,4-methylenedioxyphenyl)-serine using either benzyloxycarbonyl or phthaloyl group before dealkylation followed by deprotection of the amino group results in obtaining Droxidopa in high yields and purity.

Provided herein are methods of making the compound of Formula I: ##STR00001##
and certain intermediates involved in such process.

Provided herein are methods of making the compound of Formula I: ##STR00001##
and certain intermediates involved in such process.

The invention relates to an overall enantio-specific synthesis of 4-chlorokynurenine compounds, in particular L-4-chlorokynurenine, with improved yields. Large-scale syntheses are disclosed. The invention also relates to novel intermediates in the synthesis of L-4-chlorokynurenine.

The invention relates to an overall enantio-specific synthesis of 4-chlorokynurenine compounds, in particular L-4-chlorokynurenine, with improved yields. Large-scale syntheses are disclosed. The invention also relates to novel intermediates in the synthesis of L-4-chlorokynurenine.

A method for preparing (2S,3S)-3-amino-bicyclo[2.2.2]octane-2-carboxylate is in the field of pharmaceutical intermediate synthesis. The method uses 3-carbonyl-bicyclo[2.2.2]octane-2-carboxylate as the starting material and performs reductive amination, alkalinity configuration flip, and hydrogenation to remove the protecting group in sequence to obtain the target product. This synthesis method of (2S,3S)-3-amino-bicyclo[2.2.2]octane-2-carboxylate is characterized by a novel route, mild reaction conditions and low cost, with a yield of more than 65%.

A method for preparing (2S,3S)-3-amino-bicyclo[2.2.2]octane-2-carboxylate is in the field of pharmaceutical intermediate synthesis. The method uses 3-carbonyl-bicyclo[2.2.2]octane-2-carboxylate as the starting material and performs reductive amination, alkalinity configuration flip, and hydrogenation to remove the protecting group in sequence to obtain the target product. This synthesis method of (2S,3S)-3-amino-bicyclo[2.2.2]octane-2-carboxylate is characterized by a novel route, mild reaction conditions and low cost, with a yield of more than 65%.

Provided herein are novel solid forms of each of four compounds: (1) heptadecan-9-yl 8-((2-hydroxyethyl)amino)octanoate (“Compound 1”), (2) heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate (“Compound 2”), (3) heptadecan-9-yl 8-((2-hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate (“Compound 3”), and (6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate (“MC3”), and related compositions and methods.

Provided herein are novel solid forms of each of four compounds: (1) heptadecan-9-yl 8-((2-hydroxyethyl)amino)octanoate (“Compound 1”), (2) heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate (“Compound 2”), (3) heptadecan-9-yl 8-((2-hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate (“Compound 3”), and (6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate (“MC3”), and related compositions and methods.