Yield:1082041-52-8 27%

Reaction Conditions:

in tetrahydrofuran at -40; for 3 h;Bartoli Indole Synthesis;

Steps:

72.C3

The 5-fluoro-7-methyl-lH-indole is prepared from 4-fluoro-2-methyl- 1 - nitrobenzene using Bartoli Indole synthesis (4-fluoro-2-methyl-l -nitrobenzene in THF (10 vol) was treated with 4 eq of 1M Vinyl Magnesium bromide at -40oC for 3 h. After completion of the reaction by TLC, the reaction mixture was quenched with saturated NH₄CI and extracted with EtOAc. The combined organic layer washed with brine followed by water to get the crude. The crude was purified by combi- flash using 5% EtOAc in hexane and the cleaner fractions are evaporated to get 5-fluoro-7-methyl-lH-indole with an isolated yield of 27%

References:

WO2020/176597,2020,A1 Location in patent:Paragraph 0301; 0303; 0304