The present invention relates to a cresol preparation method, wherein DTE, a byproduct produced by the cresol preparation method, is separated and recycled to a reaction step, thereby inhibiting the production of DTE.

The cresol preparation method according to the present invention is a process in which a cresol is prepared by a reaction of halo-toluene and a basic aqueous solution, and the method comprises a step of separating DTE, a byproduct of the process, and re-feeding DTE to the reaction step of halo-toluene and the basic aqueous solution.

The present invention relates to a cresol preparation method, wherein DTE, a byproduct produced by the cresol preparation method, is separated and recycled to a reaction step, thereby inhibiting the production of DTE.

The cresol preparation method according to the present invention is a process in which a cresol is prepared by a reaction of halo-toluene and a basic aqueous solution, and the method comprises a step of separating DTE, a byproduct of the process, and re-feeding DTE to the reaction step of halo-toluene and the basic aqueous solution.

The present invention relates to a process for the preparation of crisaborole of formula (I):

##STR00001##

by preparing intermediates of formulas (II) and (III):

##STR00002##

The present invention relates to a process for the preparation of crisaborole of formula (I):

##STR00001##

by preparing intermediates of formulas (II) and (III):

##STR00002##

The present invention relates to a process for the preparation of crisaborole of formula (I): ##STR00001## by preparing intermediates of formulas (II) and (III): ##STR00002##

The present invention relates to a process for the preparation of crisaborole of formula (I): ##STR00001## by preparing intermediates of formulas (II) and (III): ##STR00002##

The present invention relates to a process for providing a compound of formula (I): ##STR00001##
wherein R is hydrogen or R, wherein R is (C.sub.1-C.sub.4)alkyl, and Hal is a halogen, the process comprising the step of:
reacting a compound of formula (II) ##STR00002##
wherein Hal is defined as above,
with an alkali metal alkoxide of the formula XOR, wherein X is an alkali metal, and R is defined as above.

The present invention relates to a process for providing a compound of formula (I): ##STR00001##
wherein R is hydrogen or R, wherein R is (C.sub.1-C.sub.4)alkyl, and Hal is a halogen, the process comprising the step of:
reacting a compound of formula (II) ##STR00002##
wherein Hal is defined as above,
with an alkali metal alkoxide of the formula XOR, wherein X is an alkali metal, and R is defined as above.

The present invention relates to a process for providing a compound of formula (I): ##STR00001##
wherein R is hydrogen or R, wherein R is (C.sub.1-C.sub.4)alkyl, and Hal is a halogen, the process comprising the step of:
reacting a compound of formula (II) ##STR00002##
wherein Hal is defined as above,
with an alkali metal alkoxide of the formula XOR, wherein X is an alkali metal, and R is defined as above.

The present invention relates to a process for providing a compound of formula (IV): ##STR00001##
wherein R.sup.1 and R.sup.2 are each independently C.sub.1-C.sub.4 alkyl, and Hal is independently Cl or Br, the process comprising the steps of: (i) reacting a compound of formula (II) ##STR00002##
wherein R.sup.1 and Hal is defined as above, to obtain a compound of formula (III) ##STR00003##
wherein R.sup.1 and Hal is defined as above, and (ii) reacting the compound of formula (III) to obtain the compound of formula (IV).