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Abstract: A novel efficient method for vapor-phase synthesis of 3-methylindole from aniline and glycerol has been developed over Cu-based catalysts. The catalysts were characterized by BET, XRD, H2-TPR and NH3-TPD techniques. The results indicated that Cu/SiO2-Al2O3 catalyst exhibited high activity. The yield of 3-methylindole could be up to 40% when the Cu loading was 5.41wt% and the reaction temperature was 240°C. Moreover, the catalyst could be reused without obvious loss of the yield even after reaction time of 46h. Copper-based catalyst with good dispersion and large amount of weak acid sites was favorable for producing 3-methylindole. A possible reaction pathway for the catalytic synthesis of 3-methylindole was proposed. [ABSTRACT FROM AUTHOR]

Abstract: Vapor-phase methylation of indole with methanol and dimethylcarbonate (DMC) was carried out over Ni1− x Mn x Fe2O4 (x =0, 0.25, 0.5, 0.75, 1.0) type ferrospinel in a fixed-bed reactor. 3-Methylindole was found to be the major product. It was observed that systems possessing higher ‘x’ values were highly selective for 3-methylindole. A maximum yield of 54.6% with selectivity 88.3% of 3-methylindole was obtained when methanol was used as alkylating agent, while yield of 48.6% with selectivity 80.1% was obtained using DMC as alkylating agent over MnFe2O4 under optimized conditions. Ni2+/Mn2+ ionic distribution in the spinel lattice influences the acido-basic properties. Effect of alkylating agent and different reaction parameters are discussed. [Copyright &y& Elsevier]

An efficient catalyst of Cu/MIL-101 modified with CeO 2 for the conversion of biomass-derived glycerol with aniline to 3-methylindole was constructed with the yield of the aimed product up to 59%. The characterizations revealed that the addition CeO 2 to Cu/MIL-101 not only improved the dispersion of Cu particles, but also inhibited the sintering of active component, meanwhile, the number of weak acid sites of the catalyst was also greatly increased, which was favorable to the high selectivity of 3-methylindole. Moreover, the catalytic reaction mechanism was studied in depth, which both acetol and 1,2-propanediol were the intermediates in the synthesis of 3-methylindole. Unlabelled Image • Cu/MIL-101 modified with CeO 2 was fabricated for the vapor-phase synthesis of 3-methylindole. • The catalyst exhibited high activity and selectivity with the aimed product yield up to 59%. • CeO 2 could improve the dispersion of active component and inhibit the sintering of Cu particles. • In addition, the addition of CeO 2 also increased the number of weak acid sitesof the catalyst. • The catalytic mechanism for the synthesis of 3-methylindole from glycerol and aniline was studied. [ABSTRACT FROM AUTHOR]