Wash it with H2O and extract with *C6H6, dry by filtering through powdered Na2SO4, remove *C6H6 on a rotary evaporator and fractionally distil the oily residue under vacuum (b 85-88o/45mm). It boils at ca 182o at atmospheric pressure, but it cannot be distilled in air because the hot vapours flash in the condenser. [Kraus & Session J Am Chem Soc 47 2361 1925, Morris & Selwood J Am Chem Soc 63 2509 1941, Pedley et al. Trans Faraday Soc 53 1612 1957, Beilstein 4 IV 4346.]
