IMPROVEMENT IN SYNTHESIS OF BUTYLATED HYDROXYANISOLE FROM TERTIARY BUTYL HYDROQUINONE

摘要

A process for production and novel physical forms of butylated hydroxyanisole (BHA) wherein tertiary butyl hydroquinone (TBHQ) reacts within a range of about 30 to 50° C. with stoichiometrically slight excess of dimethyl sulphate and sodium hydroxide. The sodium hydroxide is added stoichiometrially in slight excess of dimethyl sulphate. A major portion of BHA formed in this reaction was recovered in a crystalline form in which 3-t-butyl-4-hydroxyanisole (3 isomer) is at least at a level of about 99%, usually at about 99.5% or more, and TBHQ at 100 ppm or less. BHA remaining in a mother liquor after crystallization was recovered by distillation and had the same purity as the crystalline BHA. The crystalline form was prepared as a low density, as well as a high density, form and could also be converted into compressed forms including flakes, tablets and the like.