Mallinckrodt, Inc.

Mallinckrodt Specialty Chemicals Company

Patton, Jerry R.

Gurusamy, Narayanasamy

Jerry R Patton

Narayanasamy Gurusamy

In a process for producing a 3-halo-halobenzene or a 1-halo-3,5-dihalobenzene, a 2-halo-4-haloaniline or 2-halo-4,6-dihaloaniline is mixed with a deaminating agent. The 2-halo-4-haloaniline or 2-halo-4,6-dihaloaniline is deaminated so as to form a corresponding 3-halo-halobenzene or 1-halo-3,5-dihalobenzene.

Preparation of 3-halo-halobenzenes and 1-halo-3,5-dihalobenzenes

Aromatic amine compounds are halogenated in the presence of a quaternary ammonium halide.

Halogenation of aromatic amine compounds

A process for the production of 2,4-dihaloaniline, especially 4-bromo-2-fluoroaniline, via the halogenation (bromination) of 2-haloaniline (2-fluoroaniline) in the presence of quaternary ammonium halide (bromide) catalyst in an inert solvent. The yield and selectivity are very high and the inventive method includes continuous processing with recycle of the catalyst/solvent mixture.

Catalytic bromination of 2-fluoroaniline

Disclosed is a practical and efficient process for preparing 6-substituted 4-chromanones from phenolic acrylate ester compounds derivable from para-substituted phenolic or thiophenolic compounds and beta-unsubstituted acrylic acid compounds which are esterifiable therewith. The process includes effecting rearrangement of a phenolic or thiophenolic acrylate ester in the presence of a rearrangement effective amount of hydrogen fluoride to the corresponding hydroxy--or mercapto (vinyl ketone) wherein the carbonyl carbon atom of the vinyl carboxy group is directly attached to the benzene ring ortho to the hydroxy or mercapto group. Thereafter, the vinyl ketone is cyclized to the corresponding 6-substituted 4-chromanone in the presence of a cyclization-effective amount of hydrogen fluoride. The 6-substituted 4-chromanones prepared by the process are useful as intermediates for preparing pharmaceutical agents.

Preparation of 6-substituted 4-chromanones

Disclosed is a practical and efficient process for preparing 6-substituted 4-chromanones from phenolic acrylate ester compounds derivable from para-substituted phenolic or thiophenolic compounds and beta-unsubstituted acrylic acid compounds which are esterifiable therewith. The process includes effecting rearrangement of a phenolic or thiophenolic acrylate ester in the presence of a rearrangement effective amount of hydrogen fluoride to the corresponding hydroxy - or mercapto (vinyl ketone) wherein the carbonyl carbon atom of the vinyl carboxy group is directly attached to the benzene ring ortho to the hydroxy or mercapto group. Thereafter, the vinyl ketone is cyclized to the corresponding 6-substituted 4-chromanone in the presence of a cyclization-effective amount of hydrogen fluoride. The 6-substituted 4-chromanones prepared by the process are useful as intermediates for preparing pharmaceutical agents.

A process is disclosed for the separation of p-fluoroaniline from a mixture, containing aniline and p-fluoroaniline, by contacting the mixture with a mineral acid in the presence of an organic solvent. The corresponding salt of p-fluoro-aniline is insoluble and can easily be isolated by conventional means such as filtration. If desired, the isolated salt can be converted to p-fluoroaniline by reaction with a base.

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Ballwin, MO, United States of America

Jerry R Patton