| abstract |
A method for producing 5-(4'-hydroxyphenyl)hydantoin by first anhydrously mixing 4-hydroxyacetophenone, a C1 to C5 alkyl nitrite, a C5 or less secondary alcohol, and anhydrous hydrogen chloride to form an intermediate; and then reacting the intermediate with urea, water and aqueous concentrated hydrogen chloride to thereby produce 5-(4'-hydroxyphenyl)hydantoin. The 5-(4'-hydroxyphenyl)hydantoin may then be hydrolyzed to produce p-hydroxyphenylglycine. |