[OH-].[K+].[N:3]1[CH:8]=[CH:7][C:6]([CH:9]=[O:10])=[CH:5][CH:4]=1.[N+:11]([CH2:13][C:14]([N:16]1[CH2:21][CH2:20][N:19]([CH3:22])[CH2:18][CH2:17]1)=[O:15])#[C-:12]>CO>[N:3]1[CH:8]=[CH:7][C:6]([C@@H:9]2[O:10][CH:12]=[N:11][C@H:13]2[C:14]([N:16]2[CH2:17][CH2:18][N:19]([CH3:22])[CH2:20][CH2:21]2)=[O:15])=[CH:5][CH:4]=1To a stirred and cooled (0° C.) solution of KOH (0.335 g, 5.98 mmol) in 7 mL MeOH were added successively pyridine-4-carbaldehyde (0.705 g, 6.58 mmol) and 2-isocyano-1-(4-methyl-piperazin-1-yl)-ethanone VIB 01128 (1.00 g, 6.58 mmol). The mixture was stirred at 0° C. until precipitation and concentrated. The mixture was partitioned between EtOAc (20 mL) and H2O (10 mL). The aqueous layer was extracted twice with EtOAc (60 mL). The EtOAc fractions were combined, washed twice with brine (2×10 mL), dried over MgSO4 and filtered. After evaporation and drying trans-(4,5-dihydro-5-(pyridin-4-yl)oxazol-4-yl)(4-methylpiperazin-1-yl)methanone VIB 01130 was obtained (1.282 g, 78% yield) as a yellow oil.
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