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##

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##

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##

The present disclosure is related to an improved and efficient process for preparation of (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine which comprises: (a) N-acylation of 3-Amino-4-methyl pyridine; (b) Quarternization of 3-Acetylamino-4-methyl pyridine using benzyl halide; (c) Partial reduction of quarternized 3-Acetylamino-4-methyl pyridine by Sodium borohydride in Methanol or water; (d) Hydrolysis of partially reduced product to 1-Benzyl-4-methylpiperidin-3-one in presence of acid; (e) Reductive amination of 1-Benzyl-4-methylpiperidin-3-one using Methanolic methylamine in presence of Titanium(IV) isopropoxide in Methanol; (f) Resolution of 1-Benzyl-4-methylpiperidin-3-yl)-methylamine using Ditoluoyl (L) tartaric acid to get (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine. The disclosure is also related to novel intermediates: ##STR00001##
wherein R, R and X are as described in the specification.

The present disclosure is related to an improved and efficient process for preparation of (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine which comprises: (a) N-acylation of 3-Amino-4-methyl pyridine; (b) Quarternization of 3-Acetylamino-4-methyl pyridine using benzyl halide; (c) Partial reduction of quarternized 3-Acetylamino-4-methyl pyridine by Sodium borohydride in Methanol or water; (d) Hydrolysis of partially reduced product to 1-Benzyl-4-methylpiperidin-3-one in presence of acid; (e) Reductive amination of 1-Benzyl-4-methylpiperidin-3-one using Methanolic methylamine in presence of Titanium(IV) isopropoxide in Methanol; (f) Resolution of 1-Benzyl-4-methylpiperidin-3-yl)-methylamine using Ditoluoyl (L) tartaric acid to get (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine. The disclosure is also related to novel intermediates: ##STR00001##
wherein R, R and X are as described in the specification.

A method for separating a homogeneous catalyst from a solution includes forming a host-guest compound between a first isomer of the catalyst and inclusion compound in the solution and isolating the host-guest compound from the solution. The catalyst may be released from the inclusion compound by converting the first isomer of the catalyst to a second isomer of the catalyst.

A method for separating a homogeneous catalyst from a solution includes forming a host-guest compound between a first isomer of the catalyst and inclusion compound in the solution and isolating the host-guest compound from the solution. The catalyst may be released from the inclusion compound by converting the first isomer of the catalyst to a second isomer of the catalyst.

An improved method is used for preparing triacetone amine while recycling the by-products. This involves treating the crude product from triacetone amine preparation, which leads to an increase in the content of compounds which react readily with ammonia. This method enables efficient recycling of the by-products formed in the synthesis of triacetone amine.

A chemical reaction is catalyzed in an organic solvent using a water soluble N-heterocyclic carbene homogeneous catalyst to form a reaction mixture. An aqueous phase in the reaction mixture. A solvent in which the catalyst is insoluble is added to the reaction mixture, causing the catalyst to migrate to the aqueous phase to form a catalyst-laden aqueous phase. The catalyst is extracted from the catalyst-laden aqueous phase.

A chemical reaction is catalyzed in an organic solvent using a water soluble N-heterocyclic carbene homogeneous catalyst to form a reaction mixture. An aqueous phase in the reaction mixture. A solvent in which the catalyst is insoluble is added to the reaction mixture, causing the catalyst to migrate to the aqueous phase to form a catalyst-laden aqueous phase. The catalyst is extracted from the catalyst-laden aqueous phase.