Process for production of aralkyloxypyrrolidine derivative
View Patent ↗The present invention provides a process for producing a 3-aralkyloxypyrrolidine derivative which is important for production of pharmaceutical products and the like. In the present invention, a N-protected-3-hydroxypyrrolidine is converted into a N-protected-3-aralkyloxypyrrolidine by allowing an aralkyl halide to act in the presence of a base and at least one of a metal halide and a phase-transfer catalyst followed by deprotecting a N-protecting group to convert it to a 3-aralkyloxypyrrolidine derivative and subsequently treating the derivative in a solvent containing a polar solvent, thereby obtaining the 3-aralkyloxypyrrolidine derivative as a crystal. According to the present invention, a 3-aralkyloxypyrrolidine derivative of high purity can be produced conveniently and efficiently on an industrial scale.
1. A process for producing a crystallized 3-aralkyloxypyrrolidine derivative (2) comprising subjecting a non-crystallized 3-aralkyloxypyrrolidine derivative (2) to a crystallization process using a solvent comprising a polar organic solvent to obtain the crystallized 3-aralkyloxypyrrolidine derivative (2),
wherein the 3-aralkyloxypyrrolidine derivative (2) is represented by the following formula (2):
wherein R represents a benzyl group; and HX represents a mineral acid, sulfonic acid, carboxylic acid or amino acid.
2. The process according to claim 1 , wherein the polar organic solvent is an ester solvent and/or an alcohol solvent.
3. The process according to claim 1 , wherein the crystallization process comprises adding a seed crystal.
4. The process according to claim 1 , further comprising, before the crystallization process, purifying the non-crystallized 3-aralkyloxypyrrolidine derivative (2) by a series of operations of:
A) treating an aqueous layer with a base after removing an organic layer from a two-phase mixture of water and an organic solvent containing a 3-aralkyloxypyrrolidine derivative (2);
B) extracting a free amine of the 3-aralkyloxypyrrolidine derivative (2) using an organic solvent; and
C) treating the free amine with an acid to convert the 3-aralkyloxypyrrolidine derivative (2) to the non-crystallized 3-aralkyloxypyrrolidine derivative (2).
5. The process according to claim 1 or 4 , wherein the non-crystallized 3-aralkyloxypyrrolidine derivative (2) is obtained by removing a N-protecting group of a N-protected-3-aralkyloxypyrrolidine (1) represented by formula (1);
wherein R represents a benzyl group; and P represents a protecting group of an amino group.
6. The process according to claim 5 , wherein the N-protected-3-aralkyloxypyrrolidine (1) is obtained by 0-aralkylation of a hydroxyl group of N-protected-3-hydroxypyrrolidine represented by formula (5);
wherein P represents a protecting group of an amino group.
7. The process according to claim 1 or 4 , wherein the non-crystallized 3-aralkyloxypyrrolidine derivative (2) is optically active.
8. The process according to claim 5 , wherein the N-protected-3-aralkyloxypyrrolidine (1) is one obtained by 0-aralkylation of a N-protected-3-hydroxypyrrolidine represented by formula (5) by allowing an aralkyl halide to act in the presence of a base and at least one of a metal halide and a phase-transfer catalyst:
wherein P represents a protecting group of an amino group.
9. The process according to claim 6 , wherein the pyrrolidine derivatives represented by the above formula (1) and (5) are optically active.
10. The process according to claim 1 , wherein the crystallized 3-aralkyloxypyrrolidine derivative (2) is optically active, and/or the non-crystallized 3-aralkyloxypyrrolidine derivative (2) is optically active.