Dsm N.v.

Astra Zeneca U.k. Limited

Robert Patrick Hof

Petrus Johannes Hermsen

Ronus De Bode

Wilhelmus Zwaan

The invention relates to a process for the conversion of group X in a 2-(6-substituted)-1,3-dioxane-4yl) acetic acid derivative according to formula 2 into a group OY in the presence of a phase transfer catalyst and an oxylating agent, by using as a phase transfer catalyst a quarternary phosphonium ion and by using as an oxylating agent an OY-ion. X stands for a halogen and R1, R2 and R3 are each independently a C1&#x2013;4 alkylgroup or R1 and R2 together with the C-atom to which they are bound form a 5- or 6-membered cycloalkyl; Y stands for RA-CO&#x2014; or for RB&#x2014;SO2- with RA, RB are chosen from the group of alkyl or aryl with 1&#x2013;12 C-atoms.

Process for the preparation of 2-(6-substituted-1,3-dioxane-4-yl) acetic acid derivates

The invention relates to a process for racemising an enantiomer-enriched Schiff base of a primary amino acid amide with a strong base that is chemically reactive towards water. The reaction is conducted in an organic solvent. Preferably a metal alkoxide, a metal alkyl, a metal amide, or a metal hydride, in particular a metal alkoxide is applied as the strong base. As the Schiff base preferably N-benzylidene primary amino acid amide is used, with the primary amino acid amide preferably being derived from an aliphatic primary amino acid amide, for example tertiary-leucine amide. As organic solvent use is preferably made of an aromatic hydrocarbon, a cyclic, aliphatic hydrocarbon or a ether, in particular an aromatic hydrocarbon is applied. The invention may also be applied for the racemisation of an enantiomer-enriched primary amino acid amide.

Process for racemising an enantiomer-enriched schiff base of an amino acid amide

Process for the preparation on (1S,2R)-1-amino-2-indanol-(R,R)-tartrate methanol solvate

Process for the preparation of N-carboxy-t-leucine anhydride in which the corresponding N-carboxy-t-leucine is subjected to a cyclization with the aid of an acyl halogenide. Preferably, acetyl chloride is used as acyl halogenide. The N-carboxy-t-leucine anhydride obtained optionally is subsequently converted into a t-leucine-N-substituted amide with the aid of the corresponding amine. Preferably, methyl amine is chosen as the amine, and the reaction is carried out in a mixture of water and methanol as solvent.

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Panningen, Netherlands

Robert Patrick Hof