METHYL 4-(2-CHLOROPHENYL)-2,4-DIOXOBUTANOATE synthesis

Yield:-

Reaction Conditions:

with potassium tert-butylate in tetrahydrofuran at 0 - 20; for 2 h;

Steps:

1.1 Step 1: Synthesis of Compound 3

Compound 2 (122.22 g) and t-BuOK (145.17 g) were dissolved in tetrahydrofuran (1500 mL), and a mixture of compound 1 (80 g) and tetrahydrofuran (500 mL) was slowly added dropwise to the mixed solution at 0° C. After completion of the addition, the reaction solution was stirred at 20° C. for 2 hours. After completion of the reaction, 1 M of hydrochloric acid aqueous solution was added to the reaction solution and the pH was adjusted to 2-3. After standing for stratification, the water phase was extracted with EtOAc (3 L*2). The organic phases were combined, washed with saturated brine (3 L*3), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain compound 3. The crude product was used directly for the next step without purification. (0110) ¹H NMR (400 MHz, CDCl₃) δ=7.69-7.61 (m, 1H), 7.50-7.37 (m, 3H), 7.01-6.86 (m, 1H), 3.94 (d, J=2.5 Hz, 3H).

References:

US2021/2235,2021,A1 Location in patent:Paragraph 0109-0110