David M Walsh

US Patent:

8242305, Aug 14, 2012

Filed:

Dec 15, 2008

Appl. No.:

12/334731

Inventors:

Hitesh Batra - Herndon VA, US
Sudersan M. Tuladhar - Silver Spring MD, US
Raju Penmasta - Herndon VA, US
David A. Walsh - Palmyra VA, US

Assignee:

United Therapeutics Corporation - Silver Spring MD

International Classification:

C07C 62/00
C07C 65/00

US Classification:

562466

Abstract:

This present invention relates to an improved process to prepare prostacyclin derivatives. One embodiment provides for an improved process to convert benzindene triol to treprostinil via salts of treprostinil and to purify treprostinil.

US Patent:

8481782, Jul 9, 2013

Filed:

Jun 2, 2011

Appl. No.:

13/151465

Inventors:

Hitesh Batra - Herndon VA, US
Raju Penmasta - Ashburn VA, US
Vijay Sharma - Olney MD, US
Sudersan M. Tuladhar - Silver Spring MD, US
David A. Walsh - Spotsylvania VA, US

Assignee:

United Therapeutics Corporation - Silver Spring MD

International Classification:

C07C 51/36

US Classification:

562466

Abstract:

The present invention is directed to a novel method for preparing a synthetic intermediate for treprostinil via a stereoselective alkyne addition reaction. Also described are methods of preparing treprostinil comprising the alkyne addition reaction described herein as well as novel intermediates useful for synthesis prostacyclin derivatives, such as treprostinil.

US Patent:

8497393, Jul 30, 2013

Filed:

Jul 13, 2012

Appl. No.:

13/548446

Inventors:

Hitesh Batra - Herndon VA, US
Sudersan M. Tuladhar - Silver Spring MD, US
Raju Penmasta - Herndon VA, US
David A. Walsh - Palmyra VA, US

Assignee:

United Therapeutics Corporation - Silver Spring MD

International Classification:

C07C 62/00
C07C 65/00

US Classification:

562466

Abstract:

This present invention relates to an improved process to prepare prostacyclin derivatives. One embodiment provides for an improved process to convert benzindene triol to treprostinil via salts of treprostinil and to purify treprostinil.

US Patent:

20120190888, Jul 26, 2012

Filed:

Mar 30, 2012

Appl. No.:

13/435708

Inventors:

Hitesh Batra - Herndon VA, US
Raju Penmasta - Ashburn VA, US
Vijay Sharma - Olney MD, US
Sudersan M. Tuladhar - Silver Spring MD, US
David A. Walsh - Spotsylvania VA, US

International Classification:

C07C 51/353

US Classification:

562466

Abstract:

The present invention is directed to a novel method for preparing a synthetic intermediates for treprostinil. Also described are methods of preparing treprostinil comprising utilizing novel intermediates described herein as well as novel intermediates useful for synthesis prostacyclin derivatives, such as treprostinil.

US Patent:

20120197041, Aug 2, 2012

Filed:

Mar 30, 2012

Appl. No.:

13/435720

Inventors:

Hitesh BATRA - Herndon VA, US
Raju PENMASTA - Ashburn VA, US
Vijay SHARMA - Olney MD, US
Sudersan M. TULADHAR - Silver Spring MD, US
David A. WALSH - Spotsylvania VA, US

International Classification:

C07C 65/26
C07C 47/575
C07C 43/23
C07C 45/49

US Classification:

562466, 568311, 568442, 568654

Abstract:

The present invention is directed to a novel method for preparing a synthetic intermediates for treprostinil. Also described are methods of preparing treprostinil comprising utilizing novel intermediates described herein as well as novel intermediates useful for synthesis prostacyclin derivatives, such as treprostinil.

US Patent:

46705660, Jun 2, 1987

Filed:

Jan 19, 1984

Appl. No.:

6/572006

Inventors:

David A. Walsh - Richmond VA

Assignee:

A. H. Robins Company, Incorporated - Richmond VA

International Classification:

C07D20934

US Classification:

548485

Abstract:

This invention relates to novel compounds having the formula: ##STR1## wherein; R. sup. 1 is fluoro, chloro, bromo, lower-alkyl or nitro, R. sup. 2 is lower alkyl, lower alkoxy, fluoro, chloro, bromo, nitro or trifluoromethyl, and m and n are 0-2 with the proviso that when R. sup. 1 or R. sup. 2 are tertiary butyl or a sterically hindering lower alkyl radical, m and/or n are 1. These compounds are intermediates in the preparation of 2-aminobiphenylacetic acids, esters and metal salts thereof.

US Patent:

49607766, Oct 2, 1990

Filed:

Jan 28, 1987

Appl. No.:

7/007592

Inventors:

David A. Walsh - Richmond VA
Albert D. Cale - Mechanicsville VA

Assignee:

A. H. Robins Company, Inc. - Richmond VA

International Classification:

A61K 31495
A61K 31445
C07D40112
C07D40312

US Classification:

514252

Abstract:

Novel 4-aryl-N-[2-(dialkylamino and heterocyclicamino)alkyl]-1-piperazinecarboxamides of the formula: ##STR1## wherein B is oxygen or sulfur; Ar is selected from ##STR2## or 2, 3 or 4-pyridyl; X is selected from hydrogen, halogen, loweralkyl, loweralkoxy, amino, dimethylamino, nitro, trifluoromethyl, cyano, acetyl, acetylamino, aminocarbonyl, carboxy or loweralkylcarboxylic acid ester; Y is selected from hydrogen, halogen, loweralkyl, loweralkoxy, nitro, trifluoromethyl, cyano, acetylamino, aminocarbonyl, carboxy or loweralkyl carboxylic acid ester; Z is selected from hydrogen, loweralkyl or loweralkoxy; Q is selected from ##STR3## m is 1 to 3 inclusive; n is zero or 1; p is zero to 3 inclusive; R. sup. 1, R. sup. 2 and R. sup. 3 are loweralkyl and may be the same or different, or R. sup. 1 and R. sup. 2 taken together with the adjacent nitrogen atom may be form a heterocyclic residue; and the pharmaceutically acceptable salts thereof are disclosed.

US Patent:

42307180, Oct 28, 1980

Filed:

Jan 9, 1979

Appl. No.:

6/002150

Inventors:

David A. Walsh - Richmond VA
William J. Welstead - Richmond VA

Assignee:

A. H. Robins Company, Inc. - Richmond VA

International Classification:

C07D29502
C07D20900

US Classification:

424274

Abstract:

3,4-Epoxypyrrolidines substituted in the 1-position with alkyl, cycloalkyl and phenylalkyl are disclosed which have pharmaceutical application in cataract prevention in animals and as intermediates in preparation of trans-3-aryloxy-4-hydroxypyrrolidines. The epoxypyrrolidines are prepared by a novel route involving chlorination of pyrrolines in aqueous medium.