Ethanol → 4-chloro-3-(6-methyl-2-oxo-4-trifluoromethyl-2H-pyrimidin-1-yl)-benzoic acid ethyl ester
Reaction equation
[Cl:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[NH:11][C:12]([NH2:14])=[O:13].[F:15][C:16]([F:24])([F:23])[C:17](=O)[CH2:18][C:19](=O)[CH3:20].[CH2:25](O)[CH3:26]>>[CH2:25]([O:7][C:6](=[O:8])[C:5]1[CH:9]=[CH:10][C:2]([Cl:1])=[C:3]([N:11]2[C:19]([CH3:20])=[CH:18][C:17]([C:16]([F:24])([F:23])[F:15])=[N:14][C:12]2=[O:13])[CH:4]=1)[CH3:26]Participants
Conditions
- Temperature
- 85 °C
Procedure
To a stirred suspension of 4-chloro-3-ureido-benzoic acid (26 g, 121 mmol) in ethanol (375 mL) was added 1,1,1-trifluoro-2,4-pentanedione (28 g, 182 mmol) and concentrated (95%) sulfuric acid (50 mL). The reaction mixture was heated at 85° C. for 6 h. After cooling to room temperature, the mixture was partitioned between water (500 mL) and DCM (1 L) and to this was added 6N aq. NaOH, until pH 9-10 attained. The DCM layer was separated and dried over MgSO4 and filtered. Concentration in vacuo gave an orange oil which was purified via silica gel flash chromatography (eluting with a gradient of 10% to 25% EtOAc in hexanes). The resulting orange solid was further triturated with diethyl ether to give 4-chloro-3-(6-methyl-2-oxo-4-trifluoromethyl-2H-pyrimidin-1-yl)-benzoic acid ethyl ester (3.77 g, 9%) as a colorless solid. MS (M+H)+: 360.8, tR=2.670 min (method 1); 1H NMR (CDCl3) δ 8.16 (1H, dd, J=8.4, 2.1 Hz), 8.00 (1H, d, J=1.8 Hz), 7.70 (1H, d, J=8.4 Hz), 6.63 (1H, s), 4.39 (2H, q, J=6.9 Hz), 2.15 (3H, s), 1.39 (3H, t, J=6.9 Hz).
Workup
- concentrationconcentrated (95%) sulfuric acid (50 mL)
- temperatureAfter cooling to room temperature
- customthe mixture was partitioned between water (500 mL) and DCM (1 L)
- additionto this was added 6N aq. NaOH
- customThe DCM layer was separated
- dry with materialdried over MgSO4
- filtrationfiltered
- concentrationConcentration in vacuo
- customgave an orange oil which
- customwas purified via silica gel flash chromatography (
- washeluting with a gradient of 10% to 25% EtOAc in hexanes)
- customThe resulting orange solid was further triturated with diethyl ether
Sources & evidence
- ORD record
- ord-68abf7da56a0465abe187f2dc50ff1c0
- Source dataset
- uspto-grants-2015_02
- Patent number
- US08952161B2
Reaction notes
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