Definition
ChEBI: A substituted aniline that is ibuprofen in which the isobutyl group is replaced by a (2-methylprop-2-en-1-yl)amino group. A non-steroidal anti-inflammatory drug, it is used for treatment of inflammatory and rheumatic disorders.
Manufacturing Process
Methyl 2-(p-aminophenyl)propionate:
Methyl 2-(p-nitrophenyl)acrylate (52 g) is hydrogenated in ethanol (500 ml) in
the presence of 5% palladium-over-charcoal, while maintaining the
temperature at +5°C. The theoretical amount of hydrogen is taken up within
one hour. After separation of the catalyst and concentration to dryness, the
resulting material gives methyl 2-(p-aminophenyl)proprionate which
crystallizes: MP: = 40°-43°C.
Methyl 2-(p-methallylaminophenyl)propionate hydrochloride:
A mixture of methyl 2-(p-aminophenyl)propionate (44.75 g), methallyl
chloride (34 g) and pyridine (30 ml) in isopropanol (400 ml) is boiled during
30 hours. The solvent is removed in vacuo and the residue is taken up into
water and ether. After separation, the organic phase is washed repeatedly
with water, after which it is dried and concentrated in vacuo. The resulting oil
is fractionally distilled in vacuo (0.1 mm Hg; 5 g of oil essentially consisting of
methyl 2-(p-aminophenyl)propionate are collected at 115°-120°C; 30 g of oil
consisting of a mixture of mono- (80%) and disubstituted (20%) amines is
collected at 128°-130°C. This oil is used to prepare the hydrochloride, which
is recrystallized from ethyl acetate, to give white crystals (22.7 g) melting at 115°C. Saponification in the cold methanolic hydroxide gives the desired 2-(4-
(methallylamino)phenyl)propionic acid (alminoprofen). MP: 120°C.
