Sodium borohydride → 5-(4-Chlorophenyl)-6-(2,4-dichlorophenyl)-2-(3,4-difluorophenyl)-furo[2,3-b]pyridin-3-ol
Reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:9]=[C:10]3[C:24](=[O:25])[C:23]([C:30]4[CH:35]=[CH:34][C:33]([F:36])=[C:32]([F:37])[CH:31]=4)(C(OC)=O)[O:22][C:11]3=[N:12][C:13]=2[C:14]2[CH:19]=[CH:18][C:17]([Cl:20])=[CH:16][C:15]=2[Cl:21])=[CH:4][CH:3]=1.[BH4-].[Na+]>CCO>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[CH:9]=[C:10]3[C:24]([OH:25])=[C:23]([C:30]4[CH:35]=[CH:34][C:33]([F:36])=[C:32]([F:37])[CH:31]=4)[O:22][C:11]3=[N:12][C:13]=2[C:14]2[CH:19]=[CH:18][C:17]([Cl:20])=[CH:16][C:15]=2[Cl:21])=[CH:6][CH:7]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of 80 mg (0.14 mmol) of the product of Step B dissolved in 1 mL EtOH was added 9 mg (0.20 mmol) of sodium borohydride. The reaction mixture was stirred at RT for 5 min then partitioned between EtOAc and water. The organic layer was separated, dried (MgSO4), filtered and evaporated. The residue was then redissolved in 10 mL MeOH and 2 mL of a 2.0 N solution of sodium hydroxide was added. The reaction mixture was stirred at 80° C. for 0.5 h, then cooled to room temperature and partitioned between EtOAc and 10% aq. NaHSO4. The organic layer was separated, washed with water, dried (MgSO4), filtered and evaporated. The residue was purified on a silica gel flash chromatography column eluted with 0–20% EtOAc-hexane. Combination of the purified fractions and drying in vacuo afforded the title compound.