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Crude 5-(4-cyano-2-methoxyphenyl)-6,7-dihydro-5H-pyrrolo[1,2-c]imidazole-5-carboxylic acid (0.168 g, 0.59 mmol) is suspended in CH2Cl2 (3 mL) and cooled to 0° C. To it is added DMF (0.2 mL) followed by the addition of a CH2Cl2 solution of oxalyl chloride (0.6 mL, 2.0 M). After 2 h, 4-fluoro-N-methylbenzylamine (0.23 mL, 1.78 mmol) is added. The reaction is stirred for another 2 h, evaporated to dryness, and partitioned between EtOAc and saturated aqueous NaHCO3. The organic phase is dried (Na2SO4), filtered, and concentrated. The crude residue is purified via flash column chromatography (2-5% MeOH/CH2Cl2) to give 5-(4-cyano-2-methoxyphenyl)-6,7-dihydro-5H-pyrrolo[1,2-c]imidazole-5-carboxylic acid (4-fluorobenzyl)methylamide as a yellow solid. MS (ESI) m/z 405.2 (M+H); 1H NMR (400 MHz, CDCl3) δ ppm 2.60 (s, 3H), 2.76-2.88 (m, 2H), 2.95-3.04 (m, 1H), 3.57-3.69 (m, 1H), 3.74 (s, 3H), 4.43 (d, J=14.4 Hz, 1H), 4.58-4.70 (m, 1H), 6.79 (s, 1H), 6.86-6.94 (m, 1H), 6.96-7.05 (m, 2H), 7.10 (s, 1H), 7.19-7.25 (m, 3H), 7.55 (s, 1H). Resolution of the (R) and (S) enantiomers of the title compound is achieved by chiral HPLC using ChiralPak AD column with a 6:4 EtOH/hexane mobile phase to give enantiomer A (tr=30.2 min) and enantiomer B (tr=36.0 min).

1. customevaporated to dryness
2. custompartitioned between EtOAc and saturated aqueous NaHCO3
3. dry with materialThe organic phase is dried (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated
6. customThe crude residue is purified via flash column chromatography (2-5% MeOH/CH2Cl2)