Reaction equation
C(O[C:4](=[O:13])[C:5](=[CH:11][NH2:12])[C:6]([O:8]CC)=[O:7])C.[C:14]1([N:20]=[C:21]=[O:22])[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.[CH:23](N(CC)C(C)C)(C)[CH3:24].CC[O-].[Na+].C(O)C>ClCCCl>[CH2:23]([N:12]1[CH:11]=[C:5]([C:6]([OH:8])=[O:7])[C:4](=[O:13])[N:20]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[C:21]1=[O:22])[CH3:24]Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 100 °C
Procedure
To a solution of 2-aminomethylene-malonic acid diethyl ester (0.75 g, 4.0 mmol) and phenyl isocyanate (0.57 g, 4.4 mmol) in 1,2-dichloroethane (20 mL) was added N,N-diisopropylethylamine (0.77 mL, 4.4 mmol) and heated at 100° C. 6 h. The mixture was cooled and filtered. The solids were purified by column chromatography with 0-5% MeOH in methylene chloride. This intermediate urea was suspended in ethanol (10 mL) and 21% NaOEt in ethanol (1.29 mL, 4.0 mmol) was added. After 18 h the solvent was removed under vacuum and the residue was slurred in ethyl acetate. The organics were washed with 1M citric acid solution, water and brine. The solvent was removed under vacuum and the residue was purified by chromatography with 0-5% MeOH in dichloromethane to give 0.50 g (40%). The ester was alkylated and hydrolyzed using methods for example 92 to give 1-ethyl-2,4-dioxo-3-phenyl-1,2,3,4-tetrahydro-pyrimidine-5-carboxylic acid. 1H NMR (DMSO) δ: 12.65 (bs, 1H), 8.82 (s, 1H), 7.54-7.43 (m, 3H), 7.32-7.29 (m, 2H), 4.02 (q, 2H, J=7.1 Hz), 1.26 (t, 3H, J=7.1 Hz).
Workup
- custom6 h
- temperatureThe mixture was cooled
- filtrationfiltered
- customThe solids were purified by column chromatography with 0-5% MeOH in methylene chloride
- customAfter 18 h the solvent was removed under vacuum
- washThe organics were washed with 1M citric acid solution, water and brine
- customThe solvent was removed under vacuum
- customthe residue was purified by chromatography with 0-5% MeOH in dichloromethane
- customto give 0.50 g (40%)
Sources & evidence
- ORD record
- ord-60eb0863b3da4679966f8c4000489dcb
- Source dataset
- uspto-grants-2015_05
- Patent number
- US09029538B2
Linked notes
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