Huntsman Petrochemical Corporation

Mallinckrodt, Inc.

Carl J Schaefer

Robert A Keppel

Timothy R Felthouse

Joseph P Haar, Jr

Charles S Kuivila

A synthetic process for the preparation of amino acid esters such as methylphenidate and analogs thereof is disclosed. The process involves reacting an amino acid such as &#x3b1;-phenyl-&#x3b1;-(2-piperidinyl)acetic acid or an analog thereof with an alcohol such as methanol in the presence of an acid and a water sequestrant such as trimethyl orthoacetate. In some embodiments, the water sequestrant is added to the reaction mixture after an initial period of esterification and then the reaction is allowed to continue. The &#x3b1;-phenyl-&#x3b1;-(2-piperidinyl)acetic acid methyl ester or analog thereof is then isolated from the reaction mixture. In one variation of the process, the supernatant liquid may be recycled in subsequent runs to increase yield and product purity.

Synthesis of methylphenidate and analogs thereof

An active catalyst having a crystal structure corresponding to that of a catalyst that has been prepared and activated by the following process. A substantially pentavalent vanadium-containing compound is reacted with a pentavalent phosphorus-containing compound in an alcohol medium capable of reducing the vanadium to an oxidation state of less than +5. Molybdenum is incorporated into the product of the reaction, thereby forming a solid molybdenum-modified precursor composition. The alcohol is removed to produce a dried solid molybdenum-modified precursor composition. Shaped bodies comprising said dried solid molybdenum-modified precursor composition are formed. The dried formed molybdenum-modified catalyst precursor composition is activated to transform it into the active catalyst.

Molybdenum-modified vanadium-phosphorus oxide catalysts for the

Production of maleic anhydride using molybdenum-modified

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Crestwood, MO, United States of America

Carl J Schaefer