2-formyl-1-isopropyl-1H-pyrrole-3-carboxylic acid ethyl ester → 2-[(4-chloro-2-methyl-phenyl)-hydroxy-methyl]-1-isopropyl-1H-pyrrole-3-carboxylic acid ethyl ester

Participants

Reaction Steps

A solution (0.5 M in THF) of 4-chloro-2-methylphenylmagnesium bromide [480438-47-9] (68.8 mmol) was added to a mixture of 2-formyl-1-isopropyl-1H-pyrrole-3-carboxylic acid ethyl ester (Step A5) (68.8 mmol) in THF (160 mL) at 0° C. After stirring for 2 h, the reaction mixture was quenched with a saturated aqueous solution of NH4Cl and extracted with MTBE (2×). The combined organic phases were successively washed with water and brine, dried (Na2SO4), filtered and concentrated. The residue was suspended in hexanes, stirred for 30 min and then filtered to afford the title compound as a white solid. tR: 7.74 min (HPLC 2); ESI-MS: tR=1.26 min, [M]+318/320 (i.e. fragmented pyrrolium ion) (LC-MS 1); TLC: Rf=0.20 (1:6 EtOAc/hexanes).

Provenance & Evidence