Trifluoroacetic acid → 2-cyclopropyl-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid [1-(1-hydroxy-1-methyl-ethyl)-cyclopentyl]-amide

Participants

Reaction Steps

In a 10 mL round-bottomed flask, 2-cyclopropyl-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid [1-(1-hydroxy-1-methyl-ethyl)-cyclopentyl]-amide (207 mg, 0.45 mmol) was dissolved in CH2Cl2 (5 mL). Trifluoroacetic acid (1.7 mL) was added and the light yellow reaction mixture was stirred at room temperature for 2 h then concentrated. The residue was taken up in toluene (5 mL), concentrated and then dried under high vacuum. The residue was dissolved in CH2Cl2 (2.5 mL) and ethylenediamine (2.5 mL) was added. The reaction mixture was stirred at room temperature for 1 h then H2O and EtOAc were added. The aqueous layer was extracted with EtOAc. The combined organics were washed with H2O and brine, dried over Na2SO4 and concentrated. The residue was purified by chromatography over 12 g of SiO2 using EtOAc/hexanes (gradient: 0-90% EtOAc) to afford 79 mg (53%) of 2-cyclopropyl-5H-pyrrolo[2,3-b]pyrazine-7-carboxylic acid [1-(1-hydroxy-1-methyl-ethyl)-cyclopentyl]-amide as a white solid. MS: (M+H)+=329; mp=232.0-234.0.

Provenance & Evidence