Diisopropylethylamine → 2-[(2,3-Dihydrobenzofuran-2-carbonyl)-amino]-indan-2-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsschritte

To a 40 mL vial containing a stirring bar, 2,3-dihydro-1-benzofuran-2-carboxylic acid (0.4 g, 2.44 mmol) is charged with dry DCM (7 mL). Stirring is initiated. HBTU (922 mg, 2.43 mmol) and the DIPEA (0.95 mL, 8.0 mmol) are added. The 2-aminoindane-2-carboxylic acid ethyl ester (500 mg, 2.44 mmol) is added. The reaction is allowed to stir for 16 h. Analysis by tlc of the reaction mixture (silica, 10% MeOH/DCM) indicates complete consumption of the starting amine. The contents of the reaction flask are diluted with EtOAc (50 mL) and transferred to a separatory funnel. This is washed consecutively with dilute aqueous NaHCO3 (25 mL) and brine (25 mL), dried over MgSO4, filtered and evaporated in vacuo to provide 1.47 g of viscous yellow oil. This material is dissolved in 10 mL of DCM and purified utilizing an ISCO Companion with a 40 g cartridge of silica. The gradient is 15% EtOAc in heptanes for 3 column volumes followed by a linear gradient to 50% over 8 column volumes and then 90% EtOAc for 2 column volumes with a ramp of 1 column volume. 25 mL fractions are collected. Fractions 3 through 6 are combined and evaporated in vacuo. Pumping to a constant weight gives amorphous white solid 0.68 g.

Herkunft & Nachweise