Ethyl 2,4-dioxovalerate → HCID 178427252, compound

Reaction equation

[NH2:1][C:2]1[CH:3]=[C:4]([OH:7])[NH:5][N:6]=1.C[O-].[Na+].C([O:13][C:14](=[O:21])[C:15](=O)[CH2:16][C:17](=O)[CH3:18])C>CO>[OH:7][C:4]1[C:3]2[C:2](=[N:1][C:15]([C:14]([OH:21])=[O:13])=[CH:16][C:17]=2[CH3:18])[NH:6][N:5]=1

Participants

Procedure

5-Amino-2H-pyrazol-3-ol (3.1 g, 31.6 mmol) were suspended in 100 ml of methanol. Then sodium methoxide (5.1 g, 95 mmol) and 2,4-dioxopentanoic acid ethyl ester (5 g, 31.6 mmol) were added, and the mixture was heated up under reflux for 12 h. The solvent was removed in a rotary evaporator, water was added to the residue, the precipitate was filtered off with suction, and the filtrate was adjusted to pH 6 with dilute hydrochloric acid. The precipitated product (both precipitates) was filtered off with suction and dried. Yield: 4.9 g (70%), M+H+: 194.09.