Pfizer Corporation

Mallinckrodt, Inc.

Pharmacia Corporation

George H Klemm

Leo J Letendre

Henry T Gaud

Cynthia Snoddy

Michael Mao

Joseph P Haar, Jr

Keith G Tomazi

Brian Orr

Brian Patrick Chekal

Ronald J VanderRoest

Richard Alan Vonder Embse

Gopi Yalamanchili

Daniel Dukesherer

Rajappa Vaidyanathan

Randy Geurink

Jr Joseph Haar

The present disclosure generally related to an improved process for the preparation of various piperidine derivatives. More particularly, the present disclosure related to an improved process for preparing sufentanil base (1) and related compounds, which advantageously utilizes more cost effective and/or less hazardous reagents, including a dispersion comprising between about 50% and about 70% by weight (based on the total weight of the dispersion) of an alkali metal hydride, such as sodium hydride, as well as eliminates the need for expensive and/or time consuming purification techniques. 

Process for the preparation of sufentanil base and related compounds

This invention is directed generally to processes for the preparation of compounds of Formula I: wherein R, R, R, R, X, X, X, X, X, Xare as defined in the specification.

Processes for the preparation of 3-(4-(2,4-difluorobenzyloxy)-3-bromo-6-methyl-2-oxopyridin-1(2H)-yl)-N,4-dimethylbenzamide

A process for the qualitative preparation of 3-haloalkyl-1H-pyrazoles suitable for efficient, high payload commercial application.

Synthesis of diaryl pyrazoles

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Webster Groves, MO, United States of America

George H Klemm