IMPROVEMENT IN SYNTHESIS OF BUTYLATED HYDROXYANISOLE FROM TERTIARY BUTYL HYDROQUINONE

摘要

An improved process for production and novel physical forms of butylated hydroxyanisole (BHA) is described 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 being added stoichiometrially in slight excess of dimethyl sulphate. 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 about 99% level, usually at about 99.5% or more, and TBHQ at 100 ppm or less. BHA remaining in mother liquor after crystallization was recovered by distillation and had same purity as the crystalline BHA. The crystalline form was prepared as low density as well as high density form and further could be converted into compressed forms including flakes, tablets and the like.