Bromine → HCID 13849603, compound
Reaction equation
C([O-])(=O)C.[Na+].[Br:6]Br.[Br:8][C:9]1[C:17]2[C:12](=[N:13][C:14]([C:23]([O:25][CH2:26][CH3:27])=[O:24])=[C:15]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:16]=2)[O:11][CH:10]=1.N12CCCN=C1CCCCC2>C(Cl)Cl>[Br:6][C:10]1[O:11][C:12]2=[N:13][C:14]([C:23]([O:25][CH2:26][CH3:27])=[O:24])=[C:15]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:16]=[C:17]2[C:9]=1[Br:8]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
Sodium acetate (2.40 g, 0.0292 mol) and bromine (7.5 mL, 0.146 mol) are added to a solution of diethyl 3-bromofuro[2,3-b]pyridine-5,6-dicarboxylate (5.00 g, 0.0146 mol) in methylene chloride (150 mL). The mixture is stirred at room temperature for four days then washed with aqueous sodium bisulfate to remove unreacted bromine. The aqueous solution is then back extracted with methylene chloride. The organic solution is combined, dried over sodium sulfate and filtered. To the filtrate is added 1,8-diazabicyclo[5.4.0]undec-7-ene(4.4 mL, 0.032 mol), and the mixture is stirred at room temperature for one hour. The solution is then concentrated in vacuo. The residue is chromatographed over silica gel eluting with 20% ethyl acetate in hexane, yielding the crude 2,3-dibromofuro[2,3-b]pyridine as a white solid in 95% yields recrystallization from a methylene chloride-hexane mixture affords diethyl 2,3-dibromofuro[2,3-b]pyridine-5,6-dicarboxylate mp 96°-98° C. in 75.9% recrystallized yield.
Workup
- washthen washed with aqueous sodium bisulfate
- customto remove unreacted bromine
- extractionThe aqueous solution is then back extracted with methylene chloride
- dry with materialdried over sodium sulfate
- filtrationfiltered
- stirringthe mixture is stirred at room temperature for one hour
- concentrationThe solution is then concentrated in vacuo
- customThe residue is chromatographed over silica gel eluting with 20% ethyl acetate in hexane
- customyielding the crude 2,3-dibromofuro[2,3-b]pyridine as a white solid in 95%
- customyields
- customrecrystallization from a methylene chloride-hexane mixture
Sources & evidence
- ORD record
- ord-b39fc34e3abf4f5990890e7788c9f8ed
- Source dataset
- uspto-grants-1987_03
- Patent number
- US04650514
Reaction notes
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