Sulfonation of 1- and 2-phenylnaphthalene, 1, 1'-binaphthyl, 2, 2' -dihydroxy, 2, 2'-dimethoxy and 2, 2'-dimethoxy derivatives of 1, 1'- binaphthyl with SO~3 in dichloromethane as solvent was studied. Sulfonation of 1-phenylnaphthalene and 1, 1'-binaphthyl leads to substitution at the 4-position and subsequently at the 6- and 7- position. Upon sulfonation the more planar 2-phenylnaphthalene and 2, 2'-binaphthyl both give initially the 8-sulfonic acid derivative and subsequently a mixture of 8, 4'- and 8, 8'-disulfonic acid derivative. Sulfonation of 2, 2'-dimethoxy-1, 1'-binaphthyl gives initial the 3- and 6-sulfonic acid derivatives in an isomer ratio of approximately 13:89, monosulfonation of 2, 2'-dimesyloxy-1, 1'- binaphthyl gives the 5- and 6-sulfonic acid derivative in a ratio of 58:42. Sulfonation of 2, 2'-dihydroxy-1, 1'-binaphthyl gives initially the 5- and 6-solfonic acid derivative, the ratio of which increases upon increasing the amount of SO~3 employed from approximately 35:65 on using ≤1.0mol. of SO~3 to approximately 62:38 on using ＞6.0mol. of SO~3.

Key words: SULFUR TRIOXIDE, SULFONATION