Ethyl 2-(2-(4-nitrophenyl)-2-oxoethylamino)-2-oxoacetate → Ethyl 5-(4-nitrophenyl)-1,3-oxazole-2-carboxylate
反応式
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([C:10](=[O:20])[CH2:11][NH:12][C:13](=O)[C:14]([O:16][CH2:17][CH3:18])=[O:15])=[CH:6][CH:5]=1)([O-:3])=[O:2]>O=P(Cl)(Cl)Cl>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([C:10]2[O:20][C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[N:12][CH:11]=2)=[CH:8][CH:9]=1)([O-:3])=[O:2]参加物
3
実験手順
A solution of Ethyl 2-(2-(4-nitrophenyl)-2-oxoethylamino)-2-oxoacetate (step C product, 8.5 g) in POCl3 (55 ml) was refluxed for 6 hours. The reaction mixture was cooled, quenched with ice and neutralized with sodium carbonate. DCM was added to it and the organic and aqueous layers were separated. Organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to get dark brown residue. The residue was chromatographed on silica gel in 2:8 Ethyl acetate:Pet ether to get pale brown colored solid which was crystallized in chloroform/pet ether to yield 4.82 g (60%) of the title compound. 1HNMR (CDCl3, 300 MHz): δ 8.41 (d, 2H), 7.97 (d, 2H), 7.37 (s, 1H), 4.55 (q, 2H), 1.49 (t, 3H).