The overall sequence used for the production of multi kilograms quantity of MRTX0902 fumarate is shown in Scheme 6 below. A sample was purified by flash column chromatography on silica gel using 0 to 10% iPrOAc in heptane to obtain an analytically pure sample as a white solid which matched reported literature. . The mixture was allowed to react at 115 °C until the starting material was ≤1.0 area% by HPLC analysis (typically 24 h). The reaction was cooled to 60 °C and water [4. was added. The reaction was then cooled to 30 °C and MTBE [51. was added followed by brine 10 w/v% [34. . The biphasic mixture was stirred for 30 minutes, and the aqueous phase was discarded. The organic layer was washed with an aqueous solution of KH2PO4 12 w/v% [43.0 L] and brine 10 w/v% [17. . The biphasic mixture was stirred for 30 minutes, and the aqueous phase was discarded. The organic phase was then concentrated under reduced pressure to afford 12.5 kg of tert-butyl 2-morpholinoisonicotinate (15) as a pale-yellow oil in 97% corrected isolated yield [LCAP 98.9% -qNMR 82.5% potency -