1-methyl-2-(tributylstannyl)-1H-pyrrole → 2-amino-5-(1-methyl-1H-pyrrol-2-yl)-4-trifluoromethyl-benzoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

2-Amino-5-iodo-4-trifluoromethyl-benzoic acid methyl ester (400 mg, 1.16 mmol) and 1-methyl-2-tributylstannanyl-1H-pyrrole (643 mg, 1.5 equiv) were weighed in air and added in a flame-dried flask. [Bistriphenylphosphine]dichloropalladium (124.5 mg, 0.15 equiv) was added and the flask was closed by a septum. Dioxane (16 mL) was added and the mixture was stirred for 1 h (TLC control) at 100° C. After 1 h, 1-methyl-2-tributylstannyl-1H-pyrrole (429 mg, 1 equiv) was added and the mixture was stirred for 35 h (TLC control) at 100° C. The solvent was removed in vacuo, the residue was taken in DCM and washed with a saturated solution of NaHCO3, water and brine. The organic phase was dried over Na2SO4 and evaporated to dryness. The crude product was purified by flash chromatography (hexanes to EtOAc/hexanes (4:6)) to furnish 2-amino-5-(1-methyl-1H-pyrrol-2-yl)-4-trifluoromethyl-benzoic acid methyl ester (50 mg, 14.5%) as a yellow oil. ESI-MS: m/z 299 [M+H]+, rt 5.78 min.

Provenance & Evidence