Campbell, A. F. published the artcileThe separation of m-and p-cresols from coal-tar crude carbolic acid, Safety of 1-(Phenylsulfinyl)piperidine, the publication is Journal of Industrial and Engineering Chemistry (Washington, D. C.) (1922), 732-7, database is CAplus.
The fractions obtained by the distillation of the crude product consist principally of (1) PHOH, (2) o-cresol, (3) m- and p-cresols and (4) xylenols and other complex phenols. Fractionation of (3) gives a PhOH-free product containing 59-60% m-cresol. The sulfonation of this with 96%, H2SO4 at 40 for 6 hrs., and subsequent treatment with H2O gives an extract (A) of non-sulfonated cresols and an aqueous solution (B) of monosulfonates containing 78-80% of the m-compound B is converted into the NH4 salts through the Ba salts and on fractional crystallization yields a product containing 98-100% m-cresol. The further sulfonation of A with 96% H2SO4 gives a non-sulfonated product (C) containing about 80% p-cresol and a sulfonated product (D) containing about 58% m-cresol, which is further sulfonated for obtaining the m-compound C may be treated so that a product containing 89% p-cresol is obtained.
Journal of Industrial and Engineering Chemistry (Washington, D. C.) published new progress about 4972-31-0. 4972-31-0 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-(Phenylsulfinyl)piperidine, and the molecular formula is C11H15NOS, Safety of 1-(Phenylsulfinyl)piperidine.
Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem