Hydrochloric Acid → HCID 57105160, compound

Participants

Reaction Steps

A mixture of 4-methoxypyridine (0.4 mol) in THF (1000 ml) was stirred and cooled in a 2-propanol/CO2 bath. Ethyl chloroformate (0.4 mol) was added dropwise and the mixture was stirred for 3 hours while cooling (mixture I). In another round-bottom flask, the Grignard-reagent was prepared: Mg (0.44 mol) was stirred in a small amount of (C2H5)2O. Some 12 was added. A small amount of 1,2-dichloro-4-(chloromethyl)-benzene was added. Then, 1,2-dichloro-4-(chloromethyl)benzene (0.4 mol) in (C2H5)2O (600 ml) was added dropwise at reflux temperature. The mixture was stirred for one hour (mixture II). The Grignard-reagent was decanted off, added to mixture I at <−40° C., and the resulting reaction mixture was stirred, allowing the temperature to reach RT. The reaction mixture was stirred for one hour at RT. HCl (10%, 800 ml) was added and the mixture was stirred for 30 minutes, then CH2Cl2 was added. The organic layer was separated, dried, filtered and the solvent evaporated, yielding 57.8 g (44%) of (±)-ethyl 6-[(3,4-dichlorophenyl)methyl]-1,2,3,4-tetrahydro-4-oxo-1-pyridinecarboxylate (intermediate 9).

Provenance & Evidence