Cresolsulfonic acids

Nitrocresolsulfonic Acid Explosives. See under Cresolsulfonic Acid and Denvatives in Vol 3, C558-L... 

NEGATOL. A condensation product of m-cresolsulfonic acid with formaldehyde. A polymerized dihydroxydimethyldiphenylmethanedisul-fonic acid. It is dispersible in water, forming very acidic colloidal solutions. The pH of a 5% dispersion is approximately 1.0. 

Addition of chlorosulfonic acid (one equivalent) to a solution of / -cresol 127 in carbon disulfide at —15 °C, gave p-tolyl hydrogen sulfate 128 (Equation 41). Reaction of p-cresol 127 with excess chlorosulfonic acid at room temperature yields 2-hydroxy-5-methylbenzene-1,3-disulfonyl chloride 129. o-, m- and p-Cresols were sulfonated by the action of chlorosulfonic acid at 25-105 °C and the isomeric mixture of cresolsulfonic acids by treatment with formaldehyde (2 1) gave condensation products which were useful pharmaceuticals. ... 

An electrorefining plant may operate with either an acid or an alkaline bath. The acid bath contains stannous sulfate, cresolsulfonic or phenolsulfonic acids (to retard the oxidation of the stannous tin in the solution), and free sulfuric acid with P-naphthol and glue as addition agents to prevent tree-like deposits on the cathode which may short-circuit the cells. The concentration of these addition agents must be carefliUy controlled. The acid electrolyte operates at room temperature with a current density of ca 86—108 A/m, cell voltage of 0.3 V, and an efficiency of 85%. Anodes (95 wt % tin) have a life of 21 d, whereas the cathode sheets have a life of 7 d. Anode slimes may be a problem if the lead content of the anodes is high the anodes are removed at frequent intervals and scmbbed with revolving bmshes to remove the slime (7). 

F) Preparation of Sulfonphthaleins. The preparations described involve (1) hydrolysis of o-sulfobenzoic imide (saccharin) to the ammonium salt of o-sulfobenzoic acid (2) preparation of o-sulfo-benzoic anhydride (3) preparation of phenolsulfonphthalein (phenol red) (4) bromination of phenolsulfonphthalein to tetrabromo derivative (bromophenol blue) (5) preparation of o-cresolsulfon-phthalein (cresol red) (6) bromination of o-cresolsulfonphthalein to the dibromo derivative (bromocresol purple)The equations for the steps are ... 

McClendon determined the salt error of o-cresolsulfone-phthalein and a-naphtholphthalein in mixtures of boric acid and borax with total salt concentrations as high as 0.6 N. When the salt content reaches 0.5 N, the salt correction amounts to about — 0.05, and at 0.6 N salt the correction is — 0.1. 

---