Ethyl 2,4-dioxovalerate → HCID 89649760, compound
Reaction equation
Cl.[Br:2][C:3]1[CH:4]=[CH:5][C:6]([NH:12][NH2:13])=[C:7]([CH:11]=1)[C:8]([OH:10])=[O:9].[CH2:14]([O:16][C:17](=[O:24])[C:18](=O)[CH2:19][C:20](=O)[CH3:21])[CH3:15]>CC(O)=O>[Br:2][C:3]1[CH:4]=[CH:5][C:6]([N:12]2[C:20]([CH3:21])=[CH:19][C:18]([C:17]([O:16][CH2:14][CH3:15])=[O:24])=[N:13]2)=[C:7]([CH:11]=1)[C:8]([OH:10])=[O:9]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of 5-bromo-2-hydrazinylbenzoic acid hydrochloride (60.0 g, 225.6 mmol) in AcOH (600 mL) was added ethyl-2,4-dioxovalerate (35.67 g, 225.6 mmol) followed by refluxing for 3 h. AcOH was evaporated invacuo and the residue was co-distilled with toluene (100 mL), twice. The residue was dissolved in EtOAc and washed with water until the aq. layer became neutral. The organic layer was dried over sodium sulphate and concentrated invacuo. The gummy material was triturated with diethyl ether to afford the title compound as a brown colored oil 80 g (100%), which was used without further purification for the next step. Rf=0.23 (10% MeOH in DCM); 1H NMR (400 MHz, DMSO-d6): δ 13.80-12.80 (brs, 1H), 8.08 (d, J=1.9 Hz, 1H), 7.96 (dd, J=2.4&8.3 Hz, 1H), 7.53 (d, J=8.3 Hz, 1H), 6.70 (s, 1H), 4.26 (q, J=7.2 Hz, 2H), 2.13 (s, 3H), 1.28 (t, J=7.1 Hz, 3H); ES-MS: m/z 353.1 (M+H).