Benzyl chloroformate → benzyl [(2R)-6-iodo-3,4-dihydro-2H-chromen-2-yl]methylcarbamate
Reaction equation
Cl.[I:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[O:9][C@@H:8]([CH2:13][NH2:14])[CH2:7][CH2:6]2.[CH2:15]([O:22][C:23](Cl)=[O:24])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.[OH-].[Na+]>O1CCCC1>[I:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[O:9][C@@H:8]([CH2:13][NH:14][C:23](=[O:24])[O:22][CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[CH2:7][CH2:6]2Participants
5
Procedure
To a mixture of (R)-6-iodo-chroman-2-methylamine hydrochloride of Example 10 (3.3 g, 10 mmol) and benzylchloroformate (1.57 mL, 11 mmol) in tetrahydrofuran (30 mL), cooled in an ice-water bath, was added slowly 1N aqueous sodium hydroxide in 20 minutes. The resulting mixture was stirred for 1 hour. The organic layer was separated and concentrated in vacuo. The aqueous layer was extracted with ethyl acetate (50 mL×2). The combined ethyl acetate layer was combined with the above residue and washed with water (50 mL), brine (50 mL), and dried over anhydrous sodium sulfate. Removal of the solvent in vacuo afforded the crude product as a white solid (4.2 g, 99%).
Workup
- temperaturecooled in an ice-water bath
- customThe organic layer was separated
- concentrationconcentrated in vacuo
- extractionThe aqueous layer was extracted with ethyl acetate (50 mL×2)
- washwashed with water (50 mL), brine (50 mL)
- dry with materialdried over anhydrous sodium sulfate
- customRemoval of the solvent in vacuo
Sources & evidence
- ORD record
- ord-4775c596867945de92d7cc754a756b55
- Source dataset
- uspto-grants-2004_03
- Patent number
- US06699860B2
Reaction notes
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