C(O)(=O)C.CN.C([O:9][C:10](=O)[CH2:11][N:12]1[CH:16]=[C:15]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[CH:14]=[C:13]1[CH:23]=O)C.[C:26]([BH3-])#[N:27].[Na+]>O1CCCC1>[CH3:26][N:27]1[C:10](=[O:9])[CH2:11][N:12]2[CH:16]=[C:15]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)[CH:14]=[C:13]2[CH2:23]1Acetic acid was added to a solution of methylamine (0.45 mL, 5.30 mmol, 40% in water) in tetrahydrofuran (8 mL) to adjust the pH to 6. A solution of (2-formyl-4-phenyl-pyrrol-1-yl)-acetic acid ethyl ester (680 mg, 2.65 mmol) in tetrahydrofuran (4 mL) was added and the reaction mixture stirred at ambient temperature for 45 min. Sodium cyanoborohydride (0.33 g, 5.30 mmol) was added and the reaction mixture heated at 75 C for 18 h. Concentration in vacuo yielded a residue which was partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to afford the crude product. Purification by column chromatography over silica gel (100-200 mesh) using 30% ethyl acetate in petroleum ether afforded 2-methyl-7-phenyl-1,2-dihydropyrrolo[1,2-a]pyrazin-3-one (180 mg, 30%) as a solid.
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