Acetic Acid → Oxaprozin

Participants

Reaction Steps

A clean dry reactor of 50 gallon capacity (227 liters) was charged with glacial acetic acid (92.0 kg.). With agitation benzoin hemisuccinate (25.3 kg.) prepared as described under part A and ammonium acetate (31 kg.) were added. The reaction mixture was heated to 90°-95° C. and stirred at this temperature range for 11/2 hours. Water (44.0 kg.) was carefully added to the reaction mixture and the mixture was reheated to 90°-95° C. The mixture was then transferred to another reactor of 50 gallon capacity (227 litres) through a pre-heated pressure filter. The first reactor and the filter were washed through with a mixture of glacial acetic acid (13.3 kg.) and water (6.2 kg.). The mixture in the reactor was then cooled to 10°-15° C. with agitation and the product was filtered on a ceramic filter. The product on the ceramic filter was then washed with a mixture prepared by adding glacial acetic acid (25.5 kg.) with agitation to water (12.5 kg.). The product on the filter was sucked well dry and then washed with demineralised water (10 kg.) and sucked well dry. The product was dried in a Mitchell oven at 80° C. for 16-18 hours. The yield of crude β-(4,5-diphenyloxazol-2-yl)propionic acid was 17.5 kg. (67% overall yield for parts A and B).

Provenance & Evidence