THE SYNTHESIS AND THE CHARACTERIZATION OF MONOMETHYL- AND DIMETHYLINDOLES

Abstract

All the seven monomethylindoles and 18 of the 21 possible dimethylindoles have been synthesized by unambiguous methods. Eleven were prepared by the Fischer ring closure applied to the appropriate phenylhydrazone, five of which through the appropriate phenylhydrazone of ethyl pyruvate. The rest were prepared by the Tyson ring closure. The picrates of each indole and the styphnates of all but three were prepared and their properties recorded. The three unrecorded styphnates (those of 1,6-, 5,6-, and 5,7-dimethylindole) could not be isolated without decomposition although they seemed to exist in solution.