The present invention relates to new methods of manufacturing benzoquinoline inhibitors of vesicular monoamine transporter 2 (VMAT2), and intermediates thereof.

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The present invention relates to new methods of manufacturing benzoquinoline inhibitors of vesicular monoamine transporter 2 (VMAT2), and intermediates thereof.

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The present invention relates to an environment-friendly process for selective acylation of aminophenol. In particular, the present invention relates to an environment-friendly process for selective acylation of para-aminophenol to obtain N-acetyl-para-aminophenol (APAP).

The present invention relates to an environment-friendly process for selective acylation of aminophenol. In particular, the present invention relates to an environment-friendly process for selective acylation of para-aminophenol to obtain N-acetyl-para-aminophenol (APAP).

Provided is a method for producing a substance related to 2-alkylcarbonylnaphtho[2,3-b]furan-4,9-dione that is suitable for industrial production. The present disclosure provides: a method for producing two production intermediates for 2-alkylcarbonyl[2,3-b]furan-4,9-dione by reacting commercially available 2-hydroxy-1,4-naphthoquinone with equally inexpensive, commercially available induced N,N-substituted formamide dimethyl acetal, and further reacting the product with an inexpensive commercially available 2-halo-1,4-diketone compound in the presence of water; and a substance related to the same.

The present disclosure relates to the field of medicine synthesis, and relates to a method for a racemic preparation of chiral h β-amino acids and derivatives thereof, and in particular to a method for racemizing sitagliptin intermediates.

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where R.sub.1 is hydrogen, alkyl or aryl; R.sub.2 is hydrogen, alkyl or aryl; R.sub.3 is hydrogen, alkyl, aryl or acyl; R.sub.4 is alkyl, aryl, OR′, SR′, NHR′ or NR′R″, wherein R′, R″ are hydrogen, alkyl or aryl.

The present disclosure relates to the field of medicine synthesis, and relates to a method for a racemic preparation of chiral h β-amino acids and derivatives thereof, and in particular to a method for racemizing sitagliptin intermediates.

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where R.sub.1 is hydrogen, alkyl or aryl; R.sub.2 is hydrogen, alkyl or aryl; R.sub.3 is hydrogen, alkyl, aryl or acyl; R.sub.4 is alkyl, aryl, OR′, SR′, NHR′ or NR′R″, wherein R′, R″ are hydrogen, alkyl or aryl.

A process is disclosed for the preparation of a compound of formula

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and/or an addition salt of a proton acid, wherein R.sup.1 and R.sup.2 independently represent alkyl, cycloalkyl, aryl or aralkyl, each aryl or aralkyl being optionally further substituted with alkyl, alkoxy and/or halogen.

A process is disclosed for the preparation of a compound of formula

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and/or an addition salt of a proton acid, wherein R.sup.1 and R.sup.2 independently represent alkyl, cycloalkyl, aryl or aralkyl, each aryl or aralkyl being optionally further substituted with alkyl, alkoxy and/or halogen.

The disclosure provides a method for synthesizing free base forms of (2R,6R)-hydroxynorketamine (HNK) and (2S,6S)-hydroxynorketamine. In an embodiment synthesis of (2R,6R)-hydroxynorketam-ine (HNK) includes preparation of (R)-norket-amine via chiral resolution from racemic norketamine via a chiral resolution with L-pyro-glutamic acid. The disclosure also provided crystal forms of the corresponding (2R,6R)-hydroxynorketamine (HNK) and (2S,6S)-hy-droxynorketamine hydrochloride salts.