Pyridine → 3-Bromo-5-(bromomethyl)pyridine
Reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH2:8]O)[CH:5]=[N:6][CH:7]=1.N1C=CC=CC=1.S(Cl)(C)(=O)=O.C([O-])([O-])=O.[K+].[K+].[Li+].[Br-:28]>C(Cl)Cl>[Br:1][C:2]1[CH:3]=[C:4]([CH2:8][Br:28])[CH:5]=[N:6][CH:7]=1Participants
Procedure
To a solution of 5-bromo-3-pyridylmethanol [see Kauffman, T., and Fischer, H. (1973) Chem. Ber. 106, 220-227.1] (0.525 gms, 2.79 mmol) in methylene chloride (2.6 mls) at 0° C. is added pyridine (0.26 mls, 3.21 mmol) then mesyl chloride (0.25 mls, 3.23 mmol). After stirring 2 hours, K2CO3 (0.88 gms, 6.37 mmol) is added. Stirring is continued for one hour and the ice bath is removed. The mixture is diluted with methylene chloride and washed with saturated aqueous NaHCO3. The organic layer is dried over Na2SO4 and evaporated to a viscous residue (>0.6 gms). The residue is dissolved in methylene chloride (8.8 mls) and tetrahydrofuran (4.4 mls) without further purification or characterization. LiBr powder (0.46 gms, 5.53 mmol) is introduced and the reaction is immersed in an oil bath (80° C.) for one hour. The crude mixture is concentrated and resolvated with ethyl acetate. Any remaining residue is pulverized and rinsed with methylene chloride. Combined organics are dried over Na2SO4 and evaporated to a solid (0.7 gms, 2.79 mmol; 100%). 1H NMR (CDCl3, 300 MHz) δ 8.65 (s, 1H), 8.55 (s, 1H), 7.90 (s, 1H), 4.45 (s, 2H).
Workup
- stirringStirring
- waitis continued for one hour
- customthe ice bath is removed
- additionThe mixture is diluted with methylene chloride
- washwashed with saturated aqueous NaHCO3
- dry with materialThe organic layer is dried over Na2SO4
- customevaporated to a viscous residue (>0.6 gms)
- dissolutionThe residue is dissolved in methylene chloride (8.8 mls)
- customtetrahydrofuran (4.4 mls) without further purification or characterization
- customthe reaction is immersed in an oil bath
- wait(80° C.) for one hour
- concentrationThe crude mixture is concentrated
- washrinsed with methylene chloride
- dry with materialCombined organics are dried over Na2SO4
- customevaporated to a solid (0.7 gms, 2.79 mmol; 100%)
Sources & evidence
- ORD record
- ord-75d103e11b7c4d93ac4f48944e6330ec
- Source dataset
- uspto-grants-1993_10
- Patent number
- US05250700
Reaction notes
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