# US 10,870,621 B2 · Method for preparing latanoprostene bunod, and intermediate therefor

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- Number: US 10,870,621 B2
- Document ID: US10870621B2
- Status: Granted
- Kind: B2
- Application number: 16/636,955
- Filed: 2018-08-03
- Published: 2020-05-28
- Granted: 2020-12-22
- Earliest claimed: 2017-08-09
- Assignees: Yonsung Fine Chemical Co., Ltd.
- Applicants: Yonsung Fine Chemical Co., Ltd.
- Inventors: Eun Jeong Ko; Hyun Ik Shin; Kee Young Lee; Chang Young Oh
- Web page: https://patentgrep.com/patent/US10870621B2

## CPC

- C07C 405/00: Compounds containing a five-membered ring having two side-chains in ortho position to each other, and having oxygen atoms directly attached to the ring in ortho position to one of the side-chains, one side-chain containing, not directly attached to the ring, a carbon atom having three bonds to hetero atoms with at the most one bond to halogen, and the other side-chain having oxygen atoms attached in gamma-position to the ring, e.g. prostaglandins {; Analogues or derivatives thereof}
- C07C 2601/08: the ring being saturated
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The present invention relates to a process for preparing latanoprostene bunod and an intermediate therefor. In accordance with the preparation process of the present invention, latanoprostene bunod can be efficiently and cost-effectively prepared while reducing side reactions.

## Claims

### Claim 1

A process for preparing latanoprostene bunod of the following formula (1), which comprises the steps of:
(i) subjecting a compound of the following formula (3) to esterification with a compound of the following formula (4) to obtain a compound of the following formula (5); and
(ii) subjecting the bromide of the compound of the following formula (5) to nitration:

### Claim 2 (depends on 1)

The process according to claim 1, wherein the esterification of step (i) is carried out in the presence of a base.

### Claim 3 (depends on 2)

The process according to claim 2, wherein the base is potassium carbonate.

### Claim 4 (depends on 1)

The process according to claim 1, wherein the nitration of step (ii) is carried out using silver nitrate (AgNO3).

### Claim 5 (depends on 1)

The process according to claim 1, wherein the compound of formula (3) is prepared by hydrolyzing an isopropyl ester group of a compound of the following formula (2):

### Claim 6 (depends on 5)

The process according to claim 5, wherein the hydrolysis is carried out using lithium hydroxide monohydrate.

### Claim 7

A compound of the following formula (5):

### Claim 8

A process for preparing a compound of the following formula (5), which comprises a step of:
(i) subjecting a compound of the following formula (3) to esterification with a compound of the following formula (4):