Provided are a novel process for preparing (3R,4R)-1-benzyl-N,4-dimethylpiperidin-3-amine or a salt thereof, which is an intermediate useful for the preparation of tofacitinib, an intermediate used in the process, i.e., isopropanol solvate of methyl ((3R,4R)-1-benzyl-4-methylpiperidin-3-yl)carbamate dibenzoyl-L-tartrate, an intermediate, having excellent stability, useful for the preparation of tofacitinib, i.e., (3R,4R)-1-benzyl-N,4-dimethylpiperidin-3-amine acetate, and a process for preparing tofacitinib or a pharmaceutically acceptable salt thereof.

The present invention relates to a process for the preparation of migalastat of formula (I) and intermediates useful in the synthesis thereof. The process comprises the double reductive amination reaction of a compound of formula (VI). ##STR00001##

The present invention relates to a process for the preparation of migalastat of formula (I) and intermediates useful in the synthesis thereof. The process comprises the double reductive amination reaction of a compound of formula (VI). ##STR00001##

The present application relates to methods of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylic acid or its derivatives in an environment-friendly way. The method uses L-glutamic acid as a starting material, which is first subjected to esterification reaction in the presence of an acidic reagent, and then reacted successively with 2-haloacetate and N-protecting agent, or with N-protecting agent and 2-haloacetate under a basic condition to obtain compound IV; then, the obtained compound IV is subjected to intramolecular condensation into a ring under the action of a strong base to obtain N-protecting group piperidine-5-one-2S-carboxylate (V).

The present application relates to methods of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylic acid or its derivatives in an environment-friendly way. The method uses L-glutamic acid as a starting material, which is first subjected to esterification reaction in the presence of an acidic reagent, and then reacted successively with 2-haloacetate and N-protecting agent, or with N-protecting agent and 2-haloacetate under a basic condition to obtain compound IV; then, the obtained compound IV is subjected to intramolecular condensation into a ring under the action of a strong base to obtain N-protecting group piperidine-5-one-2S-carboxylate (V).

The present application relates to methods of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylic acid or its derivatives in an environment-friendly way. The method uses L-glutamic acid as a starting material, which is first subjected to esterification reaction in the presence of an acidic reagent, and then reacted successively with 2-haloacetate and N-protecting agent, or with N-protecting agent and 2-haloacetate under a basic condition to obtain compound IV; then, the obtained compound IV is subjected to intramolecular condensation into a ring under the action of a strong base to obtain N-protecting group piperidine-5-one-2S-carboxylate (V).

The present application relates to methods of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylic acid or its derivatives in an environment-friendly way. The method uses L-glutamic acid as a starting material, which is first subjected to esterification reaction in the presence of an acidic reagent, and then reacted successively with 2-haloacetate and N-protecting agent, or with N-protecting agent and 2-haloacetate under a basic condition to obtain compound IV; then, the obtained compound IV is subjected to intramolecular condensation into a ring under the action of a strong base to obtain N-protecting group piperidine-5-one-2S-carboxylate (V).

In some aspects, the present disclosure provides methods of aminating an aromatic compound comprising reacting an aminating agent with an aromatic compound in the presence of a rhodium catalyst. In some embodiments, the methods may comprise aminating an aromatic compound which contains multiple different functional groups. The methods described herein may also be used to create bicyclic system comprising reacting an intramolecular aminating agent with an aromatic ring to obtain a second ring containing a nitrogen atom. In another aspect, the methods described herein may also be used to create a cyclic aliphatic cyclic/poly cyclic amine system comprising a reacting an intramolecular aminating agent by insertion into a C(sp3)-H bond.

In some aspects, the present disclosure provides methods of aminating an aromatic compound comprising reacting an aminating agent with an aromatic compound in the presence of a rhodium catalyst. In some embodiments, the methods may comprise aminating an aromatic compound which contains multiple different functional groups. The methods described herein may also be used to create bicyclic system comprising reacting an intramolecular aminating agent with an aromatic ring to obtain a second ring containing a nitrogen atom. In another aspect, the methods described herein may also be used to create a cyclic aliphatic cyclic/poly cyclic amine system comprising a reacting an intramolecular aminating agent by insertion into a C(sp3)-H bond.

Disclosed is a process for preparing an intermediate of anti-tumor drug niraparib and an intermediate thereof. The present invention discloses a process for preparing compound f, which comprises conducting a cyclization reaction of compound e in a solvent and in the presence of a base to give compound f. The process of the present invention does not involve the steps of catalytic reduction or catalytic coupling reaction of precious metals and chiral separation, which has advantages such as low equipment requirements, simple operation, favorable industrial production, avoiding waste liquid containing heavy metals and phosphorus, low cost and high product ee value. ##STR00001##