Patent ID: 6120653
Filing Date: 2000-09-19
Classification: C07C

Abstract:
A method for separation and purification of a t-butyl-methylphenol isomer, selected from the group consisting of 2-t-butyl-4-methylphenol and 2-t-butyl-5-methylphenol, from a t-butylcresol mixture comprising:(a) 2-t-butyl-4-methylphenol;(b) 2-t-butyl-5-methylphenol;(c) compounds having a lower boiling point than that of 2-t-butyl-4-methylphenol; and(d) compounds having a higher boiling point than that of 2-t-butyl-5-methylphenol;which method comprises:a)i) distilling said t-butylcresol mixture to obtain a distillate comprising:2-t-butyl-4-methylphenol and compounds having a lower boiling point than that of 2-t-butyl-4-methylphenol, anda bottom product comprising:2-t-butyl-5-methylphenol and compounds having a higher boiling point than that of 2-t-butyl-5-methylphenol;ii) distilling the distillate obtained in step a) i) to obtain 2-tbutyl-4-methylphenol as a bottom product; andiii) distilling the bottom product obtained in step a) i) to obtain 2-t-butyl-5-methylphenol as a distillate; orb)i) distilling said t-butylcresol mixture to obtain a bottom product comprising:compounds having a higher boiling point than that of 2-t-butyl-5-methylphenol; anda distillate comprising:compounds having a lower boiling point than that of 2-t-butyl-4-methylphenol;2-t-butyl-4-methylphenol and 2-t-butyl-5-methylphenol;ii) distilling the distillate obtained in step b) i) to obtain a bottom product comprising:2-t-butyl-4-methylphenol and 2-t-butyl-5-methylphenol; andiii) distilling the bottom product obtained in step b) ii) to obtain 2-t-butyl-4-methylphenol as a distillate and 2-t-butyl-5-methylphenol as a bottom product; orc)i) distilling said t-butylcresol mixture to obtain a bottom product comprising:compounds having a higher boiling point than that of 2-t-butyl-5-methylphenol, 2-t-butyl-4-methylphenol and 2-t-butyl-5-methylphenol; anda distillate comprising:compounds having a lower boiling point than that of 2-t-butyl-4-methylphenol;ii) distilling the bottom product obtained in step c) i) to obtaina distillate comprising:2-t-butyl-4-methylphenol and 2-t-butyl-5-methylphenol; andiii) distilling the distillate obtained in step c) ii) to obtain 2-t-butyl-4-methylphenol as a distillate and 2-t-butyl-5-methylphenol as a bottom product; ord)i) distilling said t-butylcresol mixture to obtain a bottom product comprising:compounds having a higher boiling point than that of 2-t-butyl-5-methylphenol; anda distillate comprising:compounds having a lower boiling point than that of 2-t-butyl-4-methylphenol, 2-t-butyl-4-methylphenol and 2-t-butyl-5-methylphenol;ii) distilling the distillate obtained in step d) i) to obtain 2-t-butyl-5-methylphenol as a bottom product, anda distillate comprising:compounds having a lower boiling point than that of 2-t-butyl-4-methylphenol and 2-t-butyl-4-methylphenol; andiii) distilling the distillate obtained in step d) ii) to obtain 2-t-butyl-4-methylphenol as a bottom product; ore)i) distilling said t-butylcresol mixture to obtain a bottom product comprisingcompounds having a higher boiling point than that of 2-t-butyl-5-methylphenol, 2-t-butyl-4-methylphenol and 2-t-butyl-5-methylphenol; anda distillate comprising:compounds having a lower boiling point than that of 2-t-butyl-4-methylphenol;ii) distilling the bottom product obtained in step e) i) to obtain:2-t-butyl-4-methylphenol as a distillate; anda bottom product comprising 2-t-butyl-5-methylphenol and compounds having a higher boiling point than that of 2-t-butyl-5-methylphenol; andiii) distilling the bottom product obtained in step e) ii) to obtain 2-t-butyl-5-methylphenol as a distillate.