Methods and systems for producing alkyl hydroxyalkanoates from hydroxycarboxylic acid recovery bottoms. The methods generally comprise the steps of obtaining a hydroxycarboxylic acid recovery bottom, adding a mono-alcohol to the hydroxycarboxylic acid recovery bottom to obtain a first mixture, heating the first mixture, optionally in the presence of a catalyst to form a reaction product, distilling the reaction product, and recovering an alkyl hydroxyalkanoate fraction.

The method for producing a vapor composition containing lactic acid of the present invention is capable of suppressing the generation of by-products such as acetaldehyde and carbon monoxide due to pyrolysis of a lactic acid species during vaporization. Furthermore, a lactic acid oligomer generated can be effectively used without loss, and a vapor composition containing lactic acid can be industrially efficiently produced stably for a long time. The present invention relates to a method for producing a vapor composition containing lactic acid including: feeding a liquid composition containing lactic acid to a vaporizer; mixing the liquid composition with a liquid composition containing a lactic acid oligomer contained in the vaporizer to prepare a liquid mixture; and heating the liquid mixture to vaporize part of the liquid mixture, whereby a vapor composition containing lactic acid is produced.

The present invention describes method of preparation of esters or amides of lactyl lactates of general formula I, where Z denotes to group of R—O or RR′—N and R represent alkyl, aryl or H from lactide and the lactide is in contact with a hydrocarbyl alcohol and a hydrolyzable halide in a non-chlorinated organic solvent, or an amine initiated by a hydrolysable halide or hydrogen halide solution or an ammonium hydrohalide, wherein the hydrocarbyl alcohol or amine is either aliphatic or aromatic and containing 1 to 1000 carbon atoms, preferably 1 up to 150 carbon atoms, and optionally one or more, preferably 1 to 5, —CH.sub.2— groups may be replaced by —O— groups.

Structure for annotation

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The present invention describes method of preparation of esters or amides of lactyl lactates of general formula I, where Z denotes to group of R—O or RR′—N and R represent alkyl, aryl or H from lactide and the lactide is in contact with a hydrocarbyl alcohol and a hydrolyzable halide in a non-chlorinated organic solvent, or an amine initiated by a hydrolysable halide or hydrogen halide solution or an ammonium hydrohalide, wherein the hydrocarbyl alcohol or amine is either aliphatic or aromatic and containing 1 to 1000 carbon atoms, preferably 1 up to 150 carbon atoms, and optionally one or more, preferably 1 to 5, —CH.sub.2— groups may be replaced by —O— groups.

Structure for annotation

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Methods and systems for producing alkyl hydroxyalkanoate from hydroxy carboxylic acid recovery bottoms. The methods generally comprise the steps of obtaining a hydroxy carboxylic acid recovery bottom, adding a mono-alcohol to the hydroxy carboxylic acid recovery bottom to obtain a first mixture, heating the first mixture in the presence of a catalyst to form a reaction product, distilling the reaction product, and recovering an alkyl hydroxyalkanoate fraction.

Methods and systems for producing alkyl hydroxyalkanoate from hydroxy carboxylic acid recovery bottoms. The methods generally comprise the steps of obtaining a hydroxy carboxylic acid recovery bottom, adding a mono-alcohol to the hydroxy carboxylic acid recovery bottom to obtain a first mixture, heating the first mixture in the presence of a catalyst to form a reaction product, distilling the reaction product, and recovering an alkyl hydroxyalkanoate fraction.

Provided is a method of efficiently preparing alkyl lactate from by-products which are generated during a process of converting lactic acid into lactide, or from poly(lactic acid) (PLA).

Provided is a method of efficiently preparing alkyl lactate from by-products which are generated during a process of converting lactic acid into lactide, or from poly(lactic acid) (PLA).

Provided is a method of efficiently preparing alkyl lactate from by-products which are generated during a process of converting lactic acid into lactide, or from poly(lactic acid) (PLA).

The present disclosure provides treprostinil derivatives that can act as prodrugs of treprostinil. The treprostinil derivatives can be used to treat any conditions responsive to treatment with treprostinil, including pulmonary hypertension, such as pulmonary arterial hypertension.