4-Nitrobenzoic Acid → HCID 21082091, compound

Participants

Reaction Conditions

Reaction Steps

(±)-4-(3-chlorophenyl)-3,4-dihydro-2(1H)-quinolinone (described in WO 97/21701) (0.0776 mol), then 4-nitro-benzoic acid (0.233 mol) were added at 100° C. to polyphosphoric acid (200 g). The mixture was stirred at 140° C. for 72 hours, cooled at 80° C., poured out into ice water, basified with NH4OH (concentrated) and extracted with CH2Cl2. The organic layer was separated, dried (MgSO4), filtered and the solvent was evaporated. The residue (19.4 g) was purified by column chromatography over silica gel (eluent: CH2Cl2/CH3OH 98/2; 15–35 μm). One fraction was collected and the solvent was evaporated. The residue (9.1 g) was crystallized from 2-propanone. The precipitate was filtered off and dried, yielding 8.5 g (27%) of (±)-4-(3-chlorophenyl)-3,4-dihydro-6-(4-nitrobenzoyl)-2(1H)-quinolinone, mp. 147° C. (intermediate 15).

Provenance & Evidence