Ethanol → Ethyl 2-(3,4-dihydroxyphenyl)-4-oxopyrimidin-5-carboxylate

Reaktionsgleichung

Cl.[OH:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[OH:12])[C:6]([NH2:8])=[NH:7].[O-:13][CH2:14][CH3:15].[Na+].C1(=O)O[CH:22]([O:23]C(CC)(CC)C)[O:21][C:19](=O)[CH2:18]1.[CH2:32](O)C>>[OH:2][C:3]1[CH:4]=[C:5]([C:6]2[NH:8][C:14](=[O:13])[C:15]([C:22]([O:21][CH2:19][CH3:18])=[O:23])=[CH:32][N:7]=2)[CH:9]=[CH:10][C:11]=1[OH:12]

Komponenten

Edukt 4

HCID 702Ethanol2×

HCID 2723922Sodium ethoxide

HCID 30271623,4-Dihydroxybenzamidine hydrochloride

HCID 131717023Diethylethoxymethylene malonate

Produkt 1

HCID 135708781Ethyl 2-(3,4-dihydroxyphenyl)-4-oxopyrimidin-5-carboxylate

Versuchsvorschrift

3,4-Dihydroxybenzamidine hydrochloride (3.5 g) was suspended in ethanol (10 ml) and treated with sodium ethoxide (prepared from sodium (0.43 g) and ethanol (13 ml)). The stirred mixture was cooled in an ice bath and treated dropwise with a solution of diethylethoxymethylene malonate (4.01 g) in ethanol (5 ml). The ice bath was removed and the mixture heated under reflux for 3 hours. During this time a yellow solid separated from solution. The reaction mixture was poured on to ice, acidified with conc. HCl (pHl) and the yellow solid filtered off. Recrystallisation from dimethylformamide gave ethyl 2-(3,4-dihydroxyphenyl)-4-oxopyrimidin-5-carboxylate (1.09 g); NMR (DMSO-d6) 1.3(t,3H); 4.25(q,2H); 6.85(d,1H); 7.6(dd,1H); 7.65(d,1H); 8.5(s,1H): MS m/e 276 (M+).