Secondary alkyltoluene isomerization

Claim 1

AN ISOMERIZATION PROCESS WHICH COMPRISES CONTACTING, UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS, A CHARGE CONSISTING ESSENTIALLY OF ONLY ONE SECONDARY ALKYLTOLUENE SELECTED FROM THE CLASS CONSISTING OF ORTHOISOPROPYLTOLUENE, PARA ISOPROPYTOLUENE, MIXTURES THEREOF, MIXTURES OF META ISOPROPYLTOLUENE AND A SUBSTANTIAL AMOUNT OF AT LEAST ONE OTHER ISOMER OF ISOPHPYLSTOUENE, ORTHO SECONDARY BUTYLTOLUENE, PARA SECONDARY BUTYLTOLUENE, MIXTURES OF AFORESAID SECONDARY BUTYLTOLUENES, AND MIXTURES OF META SECONDARY BUTYLTOLUENE AND A SUBSTANTIAL AMOUNT OF AT LEAST ONE ANOTHER ISOMER OR SECONDARY BUTYLTOLUENE, WITH AT LEAST 1 MOL OF BF3 PER MOL OF SECONDARY ALKYLTOLUENE CHARGED AND AT LEAST SUFFICIENT LIQUID HF TO PARTICIPATE IN COMPLEX-FORMATION AND TO DISSOLVE SAID CHARGE THEREBY FORMING A SINGLE ESSENTIALLY HOMOGENEOUS LIQUID PHASE, AT A TEMPERATURE OF NOT MORE THAN ABOUT -30* C. FOR A TIME OF NOT MORE THAN ABOUT 10 MINUTES AT -30* C. AND WHEREIN THE LOWER THE TEMPERATURE THE LONGER THE TIME OF CONTACTING PERMISSIBLE WHILE AVOIDING AN APPRECIABLE AMOUNT OF DISPROPORTIONATION REACTION, AND REMOVING HF AND BF3 FROM SAID LIQUID PHASE UNDER CONDITIONS TO ESSENTIALLY AVOID DISPROPORTIONATION REACTIONS AND RECOVERING A SECONDARY ALKYLTOLUENE FRACTION CONSISTING ESSENTIALLY OF THE META ISOMER.