Boron tribromide → 648904-56-7
Reaction equation
Cl.[CH3:2][S:3]([C:6]1[CH:11]=[CH:10][C:9]([C:12]2[CH:21]=[CH:20][C:19]3[C:14](=[CH:15][CH:16]=[C:17]([O:22]C)[CH:18]=3)[C:13]=2[O:24][C:25]2[CH:39]=[CH:38][C:28]([O:29][CH2:30][CH2:31][N:32]3[CH2:37][CH2:36][CH2:35][CH2:34][CH2:33]3)=[CH:27][CH:26]=2)=[CH:8][CH:7]=1)(=[O:5])=[O:4].B(Br)(Br)Br.C([O-])(O)=O.[Na+]>ClCCl.CO.C(OCC)(=O)C.[Cl-].[Na+].O>[CH3:2][S:3]([C:6]1[CH:7]=[CH:8][C:9]([C:12]2[C:13]([O:24][C:25]3[CH:39]=[CH:38][C:28]([O:29][CH2:30][CH2:31][N:32]4[CH2:37][CH2:36][CH2:35][CH2:34][CH2:33]4)=[CH:27][CH:26]=3)=[C:14]3[C:19](=[CH:20][CH:21]=2)[CH:18]=[C:17]([OH:22])[CH:16]=[CH:15]3)=[CH:10][CH:11]=1)(=[O:5])=[O:4]Participants
Conditions
- Temperature
- 3 °C
Procedure
Dissolve the product of Example 2 (6.45 g, 11.4 mmol) in dichloromethane (200 mL) and cool to 3° C. in an ice bath. Treat this solution with neat BBr3 (5.4 mL, 57 mmol), dropwise over 5 minutes, and stir for 3 hours at 0 to 10° C. Slowly pour the reaction mixture into a 1-liter separatory funnel containing saturated aqueous NaHCO3 (300 mL) and ice. Dilute the two-phase mixture with a solution of 7.5% MeOH in ethyl acetate (EtOAc, 400 mL) and brine (100 mL). Separate the layers and back extract the aqueous layer with 5% MeOH in EtOAc (2×150 mL). Wash the combined organic layers with brine (100 mL), dry (Na2SO4), filter and evaporate to obtain 5.3 g of crude product. Chromatograph the residue on a SiO2 column eluting the material with methanol in dichloromethane (2.5 to 12%) to give 4.99 grams of the title compound (85%). Dry at 45° C. (<2 mm of Hg) for 18 hours: mass spectrum (ion spray): m/z=518.3 (M+H).
Workup
- additionSlowly pour the reaction mixture into a 1-liter separatory funnel
- customSeparate the layers
- extractionback extract the aqueous layer with 5% MeOH in EtOAc (2×150 mL)
- washWash the combined organic layers with brine (100 mL)
- dry with materialdry (Na2SO4)
- filtrationfilter
- customevaporate
- customto obtain 5.3 g of crude product
- washChromatograph the residue on a SiO2 column eluting the material with methanol in dichloromethane (2.5 to 12%)
Sources & evidence
- ORD record
- ord-66daac4a84254514a0e53adac03ed913
- Source dataset
- uspto-grants-2009_09
- Patent number
- US07585977B2
Reaction notes
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