Hydrochloric Acid → Ethyl 3-(4-bromophenyl)-4-cyano-5-ethyl-1-methyl-1H-pyrrole-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 10 mL round bottom flask is charged with 4-cyano-5-ethyl-3-iodo-1-methyl-1H-pyrrole-2-carboxylic acid ethyl ester (200 mg, 0.602 mmol, prepared in preparation 38) and absolute ethanol (4.0 mL). To this solution is added 4-bromophenylboronic acid (242 mg, 1.20 mmol) and 2M aqueous Na2CO3 solution (0.90 mL). This mixture is degassed under house vacuum for about 20 min until no bubbles produced. Nitrogen gas is recharged into the flask and Pd(PPh3)4 (56 mg, 0.048 mmol) is quickly added. The septum cap is well sealed with copper wire and teflon tape. The mixture in this sealed flask is then heated in oil bath at 80° C. for 18-20 hours. The mixture is cooled to room temperature. It is diluted in methylene chloride (20 mL) and poured into 0.1 M HCl solution (30 mL), pH is adjusted to 7-8 with sat. aq. NaHCO3 solution. The mixture is extracted with methylene chloride (2×30 mL), and diethyl ether (2×30 mL), the combined extracts are dried over anhydrous MgSO4, filtered, and concentrated in vacuo. The residue is then purified by flash chromatography (silica gel, elution with 20% Et2O in hexanes) to provide the title compound (170 mg, 77%) as a light brown oil. Mass spectrum (m/e): 360.9 (M+1). Rf=0.4 (50% of Et2O in hexanes).

Provenance & Evidence