The present disclosure relates to a new, simple, two step synthesis of Indolmycin and its derivatives of formula (I), in 4-5 hours. Formula (I) wherein said process comprising the step of: 10 (a) reacting indole derivative with methyl magnesium bromide in a suitable solvent at a temperature in the range of 0-30⁰C, followed by adding ethyl epoxy butanone in a suitable solvent at -20⁰C for a period of 1-2 hrs and maintaining the obtained reaction mixture for 1 hr at -20⁰C to obtain a compound; and (b) passing the compound obtained at step a), base and N-methylated quinidine 15 through solid-solid continuous flow reactor for 1 minute to obtain the compound of formula (I).