[O:1]=[C:2]1[NH:7][C:6]([C:8]2[CH:13]=[CH:12][C:11]([C:14]([F:17])([F:16])[F:15])=[CH:10][CH:9]=2)=[CH:5][N:4]2[C:18]([CH:21]=[O:22])=[CH:19][CH:20]=[C:3]12.[BH4-].[Na+]>C(O)C.O1CCCC1>[OH:22][CH2:21][C:18]1[N:4]2[CH:5]=[C:6]([C:8]3[CH:13]=[CH:12][C:11]([C:14]([F:16])([F:17])[F:15])=[CH:10][CH:9]=3)[NH:7][C:2](=[O:1])[C:3]2=[CH:20][CH:19]=1A mixture of 1-oxo-3-(4-trifluoromethyl-phenyl)-1,2-dihydro-pyrrolo[1,2-a]pyrazine-6-carbaldehyde (0.02 g, 65.3 μmol) in ethanol (0.25 mL) and tetrahydrofuran (0.25 mL) cooled to 0° C. was treated with sodium borohydride (3 mg, 79.3 μmol). The reaction was stirred at 0° C. for 1 h and then was stored in the refrigerator overnight. At this time, the reaction was concentrated in vacuo. The remaining solid was triturated with water, collected by filtration, washed with water and dried in vacuo to afford 6-hydroxymethyl-3-(4-trifluoromethyl-phenyl)-2H-pyrrolo[1,2-a]pyrazin-1-one (10 mg, 50%) as an off-white solid. 1H NMR (DMSO-d6) δ ppm 7.87-7.96 (m, 3H), 7.79-7.87 (m, 2H), 7.40 (s, 1H), 6.87 (s, 1H), 5.03 (t, J=5.4 Hz, 1H), 4.50 (d, J=5.0 Hz, 2H). LC-MS calcd. for C15H12F3N2O2 [(M+H)+] 309, obsd. 309.0.
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