HCID 86683907, compound → HCID 67468383, compound

Participants

Reaction Conditions

Reaction Steps

The crude product solution of diethyl [1-(2-methoxy-4-nitrophenyl)-2-oxo-1,2-dihydropyridin-3-yl]malonate (maximum 0.12 mol) was diluted with 390 ml of water, and 39 ml of concentrated sodium hydroxide solution were slowly added. The reaction mixture was stirred at 45° C. for 90 min, cooled to RT, diluted with water and extracted three times with dichloromethane. The organic phase was discarded, and the aqueous phase was admixed with 300 ml of dichloromethane and adjusted to pH 1 at 15° C. with concentrated hydrochloric acid. Even in a weakly acidic medium, the evolution of carbon dioxide arises. After warming to RT, stirring was carried out for 1 h, then the phases were separated and the organic phase was dried over sodium sulphate, filtered and concentrated to dryness on a rotary evaporator. The residue was stirred with acetonitrile, filtered with suction, after-washed and dried in vacuo. This gave 17.4 g (49%) of the desired compound. The mother liquor was evaporated to dryness, stirred with acetonitrile and worked-up analogously. This gave a further 3.6 g (10%) of the desired compound.

Provenance & Evidence