In benzene, ninhydrin uaderg~ elecoopbilic substitution at C2 of 3,Mimethoxysniline, leadiug to the indeno(l2-b]indole (7). which can in turn be transformed into the fuswl Mole derivatbes (91, (17) aud (19), the indoleniues (15) and (I6), the it&lone (18). and the dihydmindoIe (8). The axnspondingnactianinwater~~~substitntionatc4togivecompwmd(11) 10984 D. ST. C.BLACK et& co~spon~g to the d~hy~ation products of hydroxy compounds analogous to (2) 3. In contrast, Roth and Kok have claimed that substitution para to the amino group occurs in electron rich anilines4. Re-examination of
Friedman's work by Shapiro and Chatterjie concluded that the product of the reaction between uinhydrin and 3hydroxyaniline was not the proposed hydroxy-anilino derivative, but the cyclised compound (3) 5. A related structum (4) was also proposed for the product from 3-me~oxy~i~e.
We now present our results, which establish that these structures am also incorrect, and should be the structurally isomeric compounds (5 and 6). A recent report by Bullington and Dodd has independently reached the same conclusion 6. Our results provide even more conclusive evidence, which supports most of their findings, but also corrects yet another erroneous structural assignment. R = O"H or COOH 3 R=oH 4 R=OMe 5 R=OH 6 R=OMe