Borane;tetrahydrofuran → tert-Butyl 1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate

HRID 470990Notes

Reaction equation

HRID 470990 reaction equation
O=[C:2]1[NH:7][CH2:6][C:5]2([CH2:12][CH2:11][N:10]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:9][CH2:8]2)[O:4][CH2:3]1.B.C1COCC1.CSC.B>C1COCC1>[O:4]1[C:5]2([CH2:12][CH2:11][N:10]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:9][CH2:8]2)[CH2:6][NH:7][CH2:2][CH2:3]1

Participants

5

Reactant 3

HCID 2723981Borane;tetrahydrofuranHCID 12423031(Dimethyl sulfide)trihydroboronHCID 57989097tert-Butyl 3-oxo-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate

Product 1

HCID 53302318tert-Butyl 1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of tert-butyl 3-oxo-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate (example 12, step a) (8.2 g) in THF (100 mL) was treated dropwise with borane THF complex (1M in THF, 91 mL) and the resultant mixture heated at 55° C. for 2 hours. Borane dimethylsulfide complex (2M in THF, 15.17 mL) was added and the resultant mixture heated at 55° C. for 2 hours. The mixture was cooled to room temperature and quenched with methanol, then the solvents were evaporated under reduced pressure. The residue was dissolved in methanol (250 mL) and the solution treated with N1,N2-dimethylethane-1,2-diamine (10 g) and the resultant mixture was heated at reflux for 6 hours. Further N1,N2-dimethylethane-1,2-diamine (3 g) was added and heated at reflux continued for 6 hours. The mixture was cooled to room temperature and the solvents evaporated under reduced pressure, the residue was purified by flash silica chromatography eluting with 1% triethylamine and 5% methanol in dichloromethane. Pure fractions were evaporated to dryness to afford the subtitled compound. Yield 7.40 g.

Workup

  1. customquenched with methanol
  2. customthe solvents were evaporated under reduced pressure
  3. dissolutionThe residue was dissolved in methanol (250 mL)
  4. additionthe solution treated with N1,N2-dimethylethane-1,2-diamine (10 g)
  5. temperaturethe resultant mixture was heated
  6. temperatureat reflux for 6 hours
  7. additionFurther N1,N2-dimethylethane-1,2-diamine (3 g) was added
  8. temperatureheated
  9. temperatureat reflux
  10. temperatureThe mixture was cooled to room temperature
  11. customthe solvents evaporated under reduced pressure
  12. customthe residue was purified by flash silica chromatography
  13. washeluting with 1% triethylamine and 5% methanol in dichloromethane
  14. customPure fractions were evaporated to dryness

Sources & evidence

ORD record
ord-ade69a544a004091ab5ea6fe6ab23ef2
Source dataset
uspto-grants-2014_01
Patent number
US08629271B2

Reaction notes

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