Potassium Carbonate → Benzyl 4-azido-3-hydroxyazepane-1-carboxylate

To a solution of 2,3,4,7-tetrahydro-azepine-1-carboxylic acid benzyl ester (4.5 g, 19.45 mmol) in dichloromethane (50 mL) was added m-chloroperbenzoic acid (60 mmol). The mixture was stirred at ambient temperature for 16 hours. Saturated aqueous K2CO3 solution was added and the mixture was extracted with dichloromethane. The combined organic layers were washed with saturated aqueous NaHCO3 and brine, dried with MgSO4 and evaporated under vacuum. The crude epoxide was dissolved in an 8:1 methanol/water mixture (100 mL). Ammonium chloride (3.2 g, 60 mmol) and sodium azide (3.9 g, 60 mmol) were added and the mixture was heated at 60° C. for 48 hours. Most of the solvent was removed under vacuum. The residue was extracted with ethyl acetate. The combined organic layers were washed with saturated aqueous NaHCO3 (200 mL) and brine (200 mL), dried with MgSO4 and evaporated under vacuum. Flash chromatography of the residue (hexane/ethyl acetate 3:1) gave 4-azido-3-hydroxy-azepane-1-carboxylic acid benzyl ester (3.3 g).

1. extractionthe mixture was extracted with dichloromethane
2. washThe combined organic layers were washed with saturated aqueous NaHCO3 and brine
3. dry with materialdried with MgSO4
4. customevaporated under vacuum
5. dissolutionThe crude epoxide was dissolved in an 8:1 methanol/water mixture (100 mL)
6. temperaturethe mixture was heated at 60° C. for 48 hours
7. customMost of the solvent was removed under vacuum
8. extractionThe residue was extracted with ethyl acetate
9. washThe combined organic layers were washed with saturated aqueous NaHCO3 (200 mL) and brine (200 mL)
10. dry with materialdried with MgSO4
11. customevaporated under vacuum

ORD record

ord-07a866c096f747ff86afc08728bcfbc7

Source dataset

uspto-grants-2007_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07196099B2