Ammonium formate → Tert-butyl 2-phenyl-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate

HRID 712944Notes

Reaction equation

HRID 712944 reaction equation
C([N:8]1[CH2:25][C:12]2([CH2:17][CH2:16][N:15]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:14][CH2:13]2)[O:11][CH:10]([C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)[CH2:9]1)C1C=CC=CC=1.C([O-])=O.[NH4+]>C(O)C.[OH-].[OH-].[Pd+2]>[C:26]1([CH:10]2[CH2:9][NH:8][CH2:25][C:12]3([CH2:13][CH2:14][N:15]([C:18]([O:20][C:21]([CH3:24])([CH3:22])[CH3:23])=[O:19])[CH2:16][CH2:17]3)[O:11]2)[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=1

Participants

5

Reactant 2

HCID 2723923Ammonium formateHCID 68292150Tert-butyl 10-benzyl-8-phenyl-7-oxa-3,10-diazaspiro[5.5]undecane-3-carboxylate

Product 1

HCID 68291603Tert-butyl 2-phenyl-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylateYield 93%

Reagents, catalysts & solvents 2

HCID 9942167Palladium hydroxideCatalystHCID 702EthanolSolvent

Conditions

Temperature
60 °C

Procedure

To tert-butyl 10-benzyl-8-phenyl-7-oxa-3,10-diazaspiro[5.5]undecane-3-carboxylate (1.58 g, 3.74 mmol) and Pd(OH)2 (280 mg, 0.40 mmol) in ethanol (16 mL) was added ammonium formate (1.10 g, 17.39 mmol) and the reaction mixture was heated to 60° C. for 40 min. The reaction mixture was cooled, filtered, concentrated to 10% of original volume, diluted with ethyl acetate and washed with sat. aq. NaHCO3 (pH 10)/brine. The aqueous was extracted further with ethyl acetate and the combined organics were dried over Na2SO4, filtered and concentrated in vacuo to give tert-butyl 8-phenyl-7-oxa-3,10-diazaspiro[5.5]undecane-3-carboxylate (1.15 g, 93%) as a white solid. ESI-MS m/z calc. 332.2. found 333.3 (M+1)+; Retention time: 1.13 minutes (3 min run). 1H NMR (400 MHz, CDCl3) δ 7.40-7.23 (m, 5H), 4.69 (dd, J=10.7, 2.7 Hz, 1H), 3.76 (br. s, 2H), 3.31 (t, J=10.7 Hz, 1H), 3.17-3.02 (m, 2H), 2.75 (dd, J=35.5, 12.4 Hz, 2H), 2.63 (dd, J=12.3, 10.8 Hz, 1H), 2.49 (d, J=12.5 Hz, 1H), 1.69-1.57 (m, J=12.6 Hz, 1H), 1.57-1.39 (m, 11H).

Workup

  1. temperatureThe reaction mixture was cooled
  2. filtrationfiltered
  3. concentrationconcentrated to 10% of original volume
  4. additiondiluted with ethyl acetate
  5. washwashed with sat. aq. NaHCO3 (pH 10)/brine
  6. extractionThe aqueous was extracted further with ethyl acetate
  7. dry with materialthe combined organics were dried over Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-171e699118e84103af6c2096d9317d6c
Source dataset
uspto-grants-2015_11
Patent number
US09181273B2

Reaction notes

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