Carbon tetrabromide → (R)-ethyl 4-(4-((4'-chlorobiphenyl-2-yl)(diethoxyphosphoryloxy)methyl)piperidin-1-yl)benzoate
Reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=2[C@H:14]([OH:32])[CH:15]2[CH2:20][CH2:19][N:18]([C:21]3[CH:31]=[CH:30][C:24]([C:25]([O:27][CH2:28][CH3:29])=[O:26])=[CH:23][CH:22]=3)[CH2:17][CH2:16]2)=[CH:4][CH:3]=1.C(Br)(Br)(Br)Br.[P:38]([O:45]CC)([O:42][CH2:43][CH3:44])[O:39][CH2:40][CH3:41]>N1C=CC=CC=1>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=2[C@H:14]([O:32][P:38]([O:42][CH2:43][CH3:44])([O:39][CH2:40][CH3:41])=[O:45])[CH:15]2[CH2:20][CH2:19][N:18]([C:21]3[CH:22]=[CH:23][C:24]([C:25]([O:27][CH2:28][CH3:29])=[O:26])=[CH:30][CH:31]=3)[CH2:17][CH2:16]2)=[CH:6][CH:7]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
A solution of (R)-ethyl 4-(4-((4′-chlorobiphenyl-2-yl)(hydroxy)methyl)piperidin-1-yl)benzoate (INTERMEDIATE 11A, 600 mg, 1.33 mmol), CBr4 (575 mg, 1.73 mmol), and pyridine (2 ml) at 0° C. was treated dropwise over a 10 minute period with triethyl phosphite (0.56 ml, 3.33 mmol). The solution was stirred at 0° C. for about 10 minutes and then the ice bath was removed. The reaction was stirred overnight at r.t. whereupon the excess pyridine was removed under reduced pressure and the concentrate was taken up in 50 ml of DCM. The organic layer was washed successively with 50 ml each of 0.5 N aq. HCl, saturated aqueous sodium bicarbonate, and water. The organic layers were dried over sodium sulfate, filtered and adsorbed onto silica gel. Purification by column chromatography (ISCO, 80 g silica gel column, eluting with 0→100% EtOAc/hexanes over 24 minutes) gave the title compound (500 mg, yield: 64%).
Workup
- customthe ice bath was removed
- stirringThe reaction was stirred overnight at r.t. whereupon the excess pyridine
- customwas removed under reduced pressure
- washThe organic layer was washed successively with 50 ml each of 0.5 N aq. HCl, saturated aqueous sodium bicarbonate, and water
- dry with materialThe organic layers were dried over sodium sulfate
- filtrationfiltered
- customPurification
- washby column chromatography (ISCO, 80 g silica gel column, eluting with 0→100% EtOAc/hexanes over 24 minutes)
Sources & evidence
- ORD record
- ord-478ec7fa01b34893be50e90ece5e8c08
- Source dataset
- uspto-grants-2015_04
- Patent number
- US09018381B2
Reaction notes
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