Yield:-

Reaction Conditions:

with water monomer;sodium hydroxide in tetrahydrofuran at 100; for 5 h;Sealed tube;

Steps:

1 6-methoxy-2-methylquinoline-3-carboxylic acid. Step-1:

A seal tube was charged with compound-9.1 (200 mg, 0.815 mmol) and Sodium hydroxide (179 mg, 4.48 mmol) in tetrahydrofuran (2.00 mL) and water (2.00 mL) and stirred at 100 °C for 5 h. TLC indicated complete conversion of SM to product. Then the THF was removed under reduced pressure and crude was diluted with water, washed with ethyl acetate (2 X 5 mL). Aqueous layer pH was adjusted to 5 with 10% citric acid solution and then extracted with ethyl acetate. Organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated. The crude compound-9.2 (163 mg, 92%) was used for next step without further purification.

References:

WO2022/55926,2022,A1 Location in patent:Page/Page column 44; 60