1H-Pyrrole-2-carboxylic acid, 4-(2-chloroacetyl)-, methyl ester synthesis

Yield:1415820-00-6 85%

Reaction Conditions:

with aluminum (III) chloride in dichloromethane at 0 - 20; for 1 h;

Steps:

a a) Methyl 4-(2-chloroacetyl)-1 H-pyrrole-2-carboxylate

To a cooled (0 °C) solution of aluminium(lll) chloride (2398 mg, 17.98 mmol) in DCM (20 mL) was added dropwise 2-chloroacetyl chloride (1 .49 mL, 18.78 mmol) and a solution of methyl 1 H- pyrrole-2-carboxylate (500 mg, 4.0 mmol) in DCM (5 mL) and the resulting mixture was stirred at room temperature for 1 h. After cooling to 0 °C brine was added, the organic layer was separated and the aqueous layer was extracted with DCM (x3). The combined organic phases were washed with water and saturated sodium hydrogen carbonate solution, dried over magnesium sulfate, filtered and the solvent was evaporated to dryness to yield the title compound (681 mg, 85%).MS (m/z): 202, 204 [M+1 , M+3]^{+ 1} H NMR 5 (400 MHz, DMSO -of₆): 3.85 (s, 3H), 4.92 (s, 2H), 7.17-7.32 (m, 1 H), 7.80 -7.95 (m, 1 H).

References:

WO2019/115405,2019,A1 Location in patent:Page/Page column 46