IP Library › Granted Patent US 8,119,803
Granted Patent B2
US 8,119,803 · App. 11/628,210 · Granted Feb 21, 2012

Preparation of opiate analgesics by reductive alkylation

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Quick Facts
Patent No.
US 8,119,803
App. No.
11/628,210
Granted
Feb 21, 2012
Kind
B2
Abstract

A process for preparing a compound of formula (A), (B) or (C): wherein P is H, CH 3 or a hydroxyl protecting group; X is O, a protected ketone, OH, a protected hydroxyl group or H; Y is OH, a protected hydroxyl group or H; W is C(CH 3 ) 2 OH, (CH 3 )(C(CH 3 ) 3 )OH or COCH 3 ; Z is C 2 -C 10 alkyl or C 2 -C 10 arylalkyl; and is a single bond or a double bond, is disclosed. The process includes reductive alkylation in the presence of hydrogen and a reductive alkylation catalyst.

Claims (21)

1. A process for preparing a compound of formula (1):

comprising reacting a compound of formula (D):

is no bond or a single bond with a compound of formula (G):

in the presence of hydrogen and a reductive alkylation catalyst in a solvent comprising an amine or amide;

wherein R is H or a hydroxyl protecting group;

X is O, a protected ketone, OH, or a protected hydroxyl group;

Y is OH or a protected hydroxyl group; and

Z is cyclopropyl.

2. The process according to claim 1 , wherein R is H.

3. The process according to claim 1 , wherein X is O or OH.

4. The process according to claim 1 , wherein Y is OH.

5. The process according to claim 1 , wherein R is H, X is O, and Y is OH.

6. The process according to claim 1 , wherein the solvent comprises said amide and the amide is N-methylpyrrolidinone.

7. The process according to claim 6 , wherein the solvent further comprises methanol.

8. The process according to claim 7 , wherein the solvent is a 70:30 mixture of N-methylpyrrolidinone and methanol.

9. The process according to claim 1 , wherein the solvent comprises said amide.

10. The process according to claim 1 , wherein the compound of formula (D) is noroxymorphone and the compound of formula (1) is naltrexone.

11. The process according to claim 1 , wherein the reductive alkylation catalyst is selected from the group consisting of platinum group metal catalysts, nickel catalysts, and mixtures of these.

12. The process according to claim 1 , wherein the reductive alkylation catalyst comprises palladium on carbon.

13. The process according to claim 1 , wherein the reductive alkylation catalyst comprises platinum on carbon.

14. The process according to claim 1 , wherein the reductive alkylation catalyst comprises palladium and platinum on carbon.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 7, 2022
From: JOHNSON MATTHEY PUBLIC LIMITED COMPANY
To: MACFARLAN SMITH LIMITED
Reel/Frame 061888/0166 →