Borane;tetrahydrofuran → (10, 11-Dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepin-10-yl)-[4-((3R)-3-hydroxy-2-methyl-cyclohex-1-en-1-yl)-3-methyl-phenyl]-methanone
Reaction equation
[CH2:1]1[C:5]2=[CH:6][N:7]([C:15]([C:17]3[CH:22]=[CH:21][C:20]([C:23]4[CH2:28][CH2:27][CH2:26][C:25](=[O:29])[C:24]=4[CH3:30])=[C:19]([CH3:31])[CH:18]=3)=[O:16])[C:8]3[CH:14]=[CH:13][CH:12]=[CH:11][C:9]=3[CH2:10][N:4]2[CH:3]=[CH:2]1.B.O1CCCC1>O1CCCC1.O>[CH:1]1[CH:2]=[CH:3][N:4]2[CH2:10][C:9]3[CH:11]=[CH:12][CH:13]=[CH:14][C:8]=3[N:7]([C:15]([C:17]3[CH:22]=[CH:21][C:20]([C:23]4[CH2:28][CH2:27][CH2:26][C@@H:25]([OH:29])[C:24]=4[CH3:30])=[C:19]([CH3:31])[CH:18]=3)=[O:16])[CH2:6][C:5]=12Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
(S)-(−)-tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaboro-borane [(S)-2-methyl-CBS-oxazaborolidine] (1.0 M in tetrahydrofuran, 1.06 mL, 1.06 mmol) was dissolved in anhydrous tetrahydrofuran (53.1 mL, distilled from sodium/benzophenone ketyl). To this solution was simultaneously added a solution of 3-[4-(5H,1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-10-carbonyl)-2-methyl-phenyl]-2-methyl-cyclohex-2-enone of Example 4 (2.18 g, 5.31 mmol) in anhydrous tetrahydrofuran (20 mL) via syringe pump (1.6 mL/min) and borane-tetrahydrofuran complex (1.0 M in tetrahydrofuran, 3.19 mL, 3.19 mmol) at a rate such that enone addition was complete upon addition of approximately ⅔ of the borane-tetrahydrofuran complex. Upon completion of the borane-tetrahydrofuran complex addition, the reaction mixture was diluted with water and extracted with ethyl acetate. The combined extracts were washed with 1 N sodium hydroxide, 1 N hydrochloric acid and brine and dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by flash column chromatography on silica gel eluting with 50% ethyl acetate in hexane followed by reprecipitation from diethyl ether upon addition of petroleum ether, to afford 2.02 g of the title compound as a white solid, [α]589=+34.30 (c=1, chloroform). Analytical HPLC (Chiralpak AD, 4.6×250 mm, 50% ethanol/hexane, 0.5 mL/min.) indicated an enantiomeric excess of 96.4%.
Workup
- additionwas complete upon addition of approximately ⅔ of the borane-tetrahydrofuran complex
- additionUpon completion of the borane-tetrahydrofuran complex addition
- extractionextracted with ethyl acetate
- washThe combined extracts were washed with 1 N sodium hydroxide, 1 N hydrochloric acid and brine
- dry with materialdried over anhydrous magnesium sulfate
- filtrationfiltered
- concentrationconcentrated
- customThe residue was purified by flash column chromatography on silica gel eluting with 50% ethyl acetate in hexane
- customfollowed by reprecipitation from diethyl ether upon addition of petroleum ether
Sources & evidence
- ORD record
- ord-30dd851a4e2b4aeabc5591d4db364bfd
- Source dataset
- uspto-grants-2006_04
- Patent number
- US07022699B2
Reaction notes
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