[F:1][C:2]1[C:7]([F:8])=[CH:6][CH:5]=[C:4]([F:9])[C:3]=1[CH2:10][C:11](=[O:13])[CH3:12].[C:14](O)(=O)C.N1CCCCC1.C=O>CC#N>[F:1][C:2]1[C:7]([F:8])=[CH:6][CH:5]=[C:4]([F:9])[C:3]=1[C:10](=[CH2:14])[C:11](=[O:13])[CH3:12]A solution of 18 (3.5 g, 18.6 mmol), acetic acid (0.34 ml, 5.58 mmol), piperidine (0.37 ml, 3.72 mmol), formaldehyde (6.0 g, 37% aqueous solution) in MeCN (20 mL) was heated over weekend. The conversion was about 60%. Reaction was heated to 70° C. overnight. The mixture was concentrated and extracted with MTBE and HCl (0.5N). The organic layer was washed with aqueous K2CO3 (0.5N) and water, in turns. The organic layer was concentrated. The product was isolated by chromatography column (hexane and EtOAc), yielding 31 (2.29 g, 61.5%).
Loading…
