NOVELTY - Preparing (2R,8R)-2-(2H-1,3-benzodioxol-5-yl)-6-methyl-3,6,17-triazatetracyclo(8.7.0.0(3,8).0(11,16))heptadeca-1(10),11,13,15-tetraene-4,7-dione (I) involves reacting 2-amino-3-(1H-indol-3-yl)propanoic acid (II) with di-tert-butyl dicarbonate to obtain 2-(((tert.-butoxy)carbonyl)amino)-3-(1H-indol-3-yl)propanoic acid (III). 2-(((Tert.-butoxy)carbonyl)amino)-3-(1H-indol-3-yl)propanoic acid (III) is treated with methyl 2-(chloro(methyl)amino)acetate (IV) to obtain methyl 2-(2-(((tert-butoxy)carbonyl)amino)-3-(1H-indol-3-yl)-N-methylpropanamido)acetate (V).    USE - Method for preparing (2R,8R)-2-(2H-1,3-benzodioxol-5-yl)-6-methyl-3,6,17-triazatetracyclo(8.7.0.0(3,8).0(11,16))heptadeca-1(10),11,13,15-tetraene-4,7-dione (claimed).    ADVANTAGE - The method enables to prepare (2R,8R)-2-(2H-1,3-benzodioxol-5-yl)-6-methyl-3,6,17-triazatetracyclo(8.7.0.0(3,8).0(11,16))heptadeca-1(10),11,13,15-tetraene-4,7-dione in an eco-friendly and easy manner on industrial scale.    DETAILED DESCRIPTION - Preparing (2R,8R)-2-(2H-1,3-benzodioxol-5-yl)-6-methyl-3,6,17-triazatetracyclo(8.7.0.0(3,8).0(11,16))heptadeca-1(10),11,13,15-tetraene-4,7-dione of formula (I) involves reacting 2-amino-3-(1H-indol-3-yl)propanoic acid of formula (II) with di-tert-butyl dicarbonate to obtain 2-(((tert.-butoxy)carbonyl)amino)-3-(1H-indol-3-yl)propanoic acid of formula (III). 2-(((Tert.-butoxy)carbonyl)amino)-3-(1H-indol-3-yl)propanoic acid of formula (III) is treated with methyl 2-(chloro(methyl)amino)acetate of formula (IV) to obtain methyl 2-(2-(((tert-butoxy)carbonyl)amino)-3-(1H-indol-3-yl)-N-methylpropanamido)acetate of formula (V). Methyl 2-(2-(((tert-butoxy)carbonyl)amino)-3-(1H-indol-3-yl)-N-methylpropanamido)acetate of formula (V) is deprotected with amino group to obtain 2-amino-N-chloro-3-(1H-indol-3-yl)-N-methylpropanamide of formula (VI). 2-Amino-N-chloro-3-(1H-indol-3-yl)-N-methylpropanamide of formula (VI) is treated with 2H-1,3-benzodioxole-5-carbaldehyde of formula (VII) to obtain final product..