4-Fluorophenol → Ethyl 6-(4-fluorophenoxy)nicotinate
Reaction equation
Cl[C:2]1[CH:12]=[CH:11][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH:4][N:3]=1.[F:13][C:14]1[CH:19]=[CH:18][C:17]([OH:20])=[CH:16][CH:15]=1.C([O-])([O-])=O.[Cs+].[Cs+]>CN(C=O)C>[F:13][C:14]1[CH:19]=[CH:18][C:17]([O:20][C:2]2[CH:12]=[CH:11][C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])=[CH:4][N:3]=2)=[CH:16][CH:15]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 24 °C
Procedure
To a 2-L, 3-necked, round-bottomed flask equipped with a mechanical stirrer, a thermo couple, and a condenser was added DMF (194 mL), ethyl 6-chloronicotinate (100.00 g, 0.522 mol), and 4-fluorophenol (65.09 g, 0.575 mol). A brown solution formed after stirring for 5-10 min. To the solution was then added Cs2CO3 (189.19 g, 0.575 mol) in one portion. The reaction temperature increased from 20° C. to 30° C. over 10 min without external heating and then started cooling down. The resulting suspension was stirred at rt for 2-3 h and the internal reaction temperature cooled back to 23-25° C. The reaction mixture was then heated to 60° C. and stirred for 18-20 h. HPLC analysis indicated that the reaction was complete. The heating mantle was removed and the reaction mixture was allowed to cool to 25-30° C. To the mixture was added deionized water (145.5 mL) in a steady stream over 5 min and a slight exotherm was observed. The resulting suspension was stirred at rt for 15-20 min. Two additional portions of deionized water (145.5 mL each) were added and the suspension was stirred at rt for 15-30 min. The pH of the suspension was around 9-10. The solid product was collected by vacuum filtration, rinsed thoroughly with deionized water in portions. The filter cake as dried in a filter funnel by pulling through air for 24 h. The product was isolated as a white solid (133.6 g). mp: 68.0° C. (by DSC). 1H NMR (CDCl3): δ 8.81 (d, J=2.6 Hz, 1H), 8.22 (dd, J=8.5, 2.6 Hz, 1H), 7.12 (br s, 2H), 7.10 (d, J=1.0 Hz, 2H), 6.94 (d, J=8.5 Hz, 1H), 4.38 (q, J=7.1 Hz, 2H), 4.38 (t, J=7.1 Hz, 3H). MS (ESI): M+H+=262.1.
Workup
- customA brown solution formed
- temperatureThe reaction temperature increased from 20° C. to 30° C. over 10 min
- temperaturewithout external heating
- temperaturestarted cooling down
- stirringThe resulting suspension was stirred at rt for 2-3 h
- temperatureThe reaction mixture was then heated to 60° C.
- stirringstirred for 18-20 h
- customThe heating mantle was removed
- temperatureto cool to 25-30° C
- additionTo the mixture was added deionized water (145.5 mL) in a steady stream over 5 min
- stirringThe resulting suspension was stirred at rt for 15-20 min
- additionTwo additional portions of deionized water (145.5 mL each) were added
- stirringthe suspension was stirred at rt for 15-30 min
- filtrationThe solid product was collected by vacuum filtration
- washrinsed thoroughly with deionized water in portions
- customThe filter cake as dried in a filter funnel
- waitby pulling through air for 24 h
Sources & evidence
- ORD record
- ord-0eb1d8019a964e6784722276158e0ca8
- Source dataset
- uspto-grants-2015_01
- Patent number
- US08940731B2
Reaction notes
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