3-[5-溴-2-[2-[(1S)-1-甲氧基乙基]-3-吡啶基]-1H-吲哚-3-基]-2,2-二甲基丙-1-醇

It is the ethyl ester derivative of the key carboxylic acid intermediate in the synthetic route of the KRAS inhibitor Sotorasib, belonging to the same series of pharmaceutical intermediates. The carboxyl group (-COOH) of the parent carboxylic acid is modified to an ethyl ester group (-COOCH₂CH₃), while the rest of the parent core structures, including the indole ring, bromine substituent, chiral pyridine side chain and other moieties, are completely consistent with those of the parent compound.