SYNTHESIS OF 1-SUBSTITUTED INDOLES BY THE VAPOR-PHASE REACTION OF N-SUBSTITUTED ANILINES WITH GLYCOLS AND EPOXIDES OVER A SOLID CATALYST AND A VAPOR-PHASE DEALKYLATION OF 1-ALKYLINDOLE

1-Substituted indoles 4b-h, 5c, e were synthesized in good yields by the vapour phase reaction of N-substituted anilines Ib-e with glycols 2a-c and epoxides 3a, b at 250-400 degrees C over a solid catalyst, Neobead P (Al2O3:SiO2:Na2O = 88:9:3), at atmospheric pressure. 1-Alkylindoles 4b, d, g were converted into indole (4a) in good yields by a vapour phase reaction with steam and hydrogen gas over ZnO (10%) supported on Neobead C (Al2O3) at 500-575 degrees C. These reaction pathways are discussed.