# US 8,541,609 B2 · Exemestane and its intermediates and methods of making the same

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- Number: US 8,541,609 B2
- Document ID: US8541609B2
- Status: Granted
- Kind: B2
- Application number: 13/451,034
- Filed: 2012-04-19
- Published: 2012-08-16
- Granted: 2013-09-24
- Earliest claimed: 2004-01-16
- Assignees: Cedarburg Pharmaceuticals, Inc.
- Applicants: Kevin Kunnen; Nathan W. Stehle; Scot W. Weis; John M. Pascone; Richard J. Pariza; Scott G. Van Ornum; Paul Zizelman
- Inventors: Kevin Kunnen; Nathan W. Stehle; Scot W. Weis; John M. Pascone; Richard J. Pariza; Scott G. Van Ornum; Paul Zizelman
- Web page: https://patentgrep.com/patent/US8541609B2

## CPC

- C07J 1/0011: {substituted in position 17 by a keto group}
- C07J 1/00: Normal steroids containing carbon, hydrogen, halogen or oxygen, not substituted in position 17 beta by a carbon atom, e.g. estrane, androstane
- C07J 31/006: {not covered by C07J31/003}
- C07J: STEROIDS (seco-steroids C07C)

## Abstract

A method is provided for preparing an aromatase inhibitor of formula (I) wherein each of R1, R2, R3, R4, independently, is hydrogen, halogen or C1-C6 alkyl. In one form, the aromatase inhibitor is exemestane wherein each of R1, R2, R3, R4 is hydrogen. In the method, a compound of formula (II) wherein R1, R2, R3, R4 are as defined above and R is alkylene, is reacted with a deprotonating agent and a compound of the formula R5SO2X wherein R5 is C1-C5 alkyl and X is halogen so as to obtain a compound of formula (III) wherein R1, R2, R3, R4, R5 are as defined above. The compound of Formula (III) is then reacted with a base to form an aromatase inhibitor of formula (I).

## Claims

### Claim 1

A compound of the formula (IV):
wherein each of R1, R2, R3, R4, independently, is hydrogen, halogen or C1-C6 alkyl, and R6 is SO2R5 wherein R5 is C1-C5 alkyl.

### Claim 2 (depends on 1)

The compound of claim 1 wherein each of R1, R2, R3, R4 is hydrogen.

### Claim 3 (depends on 1)

The compound of claim 1 wherein R5 is methyl.