Lithium Hexamethyldisilazide → 1h-Pyrrolo[2,3-c]pyridine-5-carboxylic acid,2,3-dibromo-1-[(4-fluorophenyl)methyl]-4-hydroxy-,ethyl ester

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Reaction Steps

To a stirring solution of ethyl 4,5-dibromo-1-(4-fluorobenzyl)-2-({(2-ethoxy-2-oxoethyl)[(4-methylphenyl) sulfonyl]amino}methyl)-1H-pyrrole-3-carboxylate (124.2 g, 184.3 mol) in anhydrous THF (1.0 L) was added LiHMDS (405 mL, 1.0M in THF, 0.405 mol) at −78° C. over 1 h. The mixture was quenched with aq. NH4Cl, extracted with ethyl acetate. The organic layer was dried over Na2SO4, and concentrated. The residue was purified by column chromatography with etyl acetate/hexane (1/1, v:v) to ethyl acetate/dichloromethane (9/1) to give the title product (52.0 g 60% yield). 1H NMR (DMSO-d6) δ ppm. 11.50 (s, 1H), 8.63 (s, 1H), 7.16 (d, J=7.2 Hz, 4H), 5.60 (s, 2H), 5.67 (s, 2H), 4.39 (q, J=7.1 Hz, 2H,), 1.33 (t, J=7.2 Hz, 3H). LC/MS (API-ES, M+H+): 473.0.

Provenance & Evidence