Hydrochloric Acid → Tert-butyl (6'-amino-2',2'-dimethyldispiro[1,3-oxazole-4,4'-chromene-3',3''-oxetan]-2-yl)carbamate

HRID 873707Notes

Reaction equation

HRID 873707 reaction equation
Br[C:2]1[CH:3]=[C:4]2[C:31](=[CH:32][CH:33]=1)[O:30][C:29]([CH3:35])([CH3:34])[C:25]1([CH2:28][O:27][CH2:26]1)[C:5]12[CH2:9][O:8][C:7]([N:10]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])C(OC(C)(C)C)=O)=[N:6]1.F[B-](F)(F)F.C([PH+](C(C)(C)C)C(C)(C)C)(C)(C)C.C[Si]([N-:58][Si](C)(C)C)(C)C.[Li+].Cl>C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].CO>[NH2:58][C:2]1[CH:3]=[C:4]2[C:31](=[CH:32][CH:33]=1)[O:30][C:29]([CH3:34])([CH3:35])[C:25]1([CH2:28][O:27][CH2:26]1)[C:5]12[CH2:9][O:8][C:7]([NH:10][C:18](=[O:19])[O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[N:6]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 2733832Lithium HexamethyldisilazideHCID 2734635Tri-tert-butylphosphine tetrafluoroborateHCID 86724228Di-tert-butyl (6'-bromo-2',2'-dimethyldispiro[1,3-oxazole-4,4'-chromene-3',3''-oxetan]-2-yl)imidodicarbonate

Product 1

HCID 86724249Tert-butyl (6'-amino-2',2'-dimethyldispiro[1,3-oxazole-4,4'-chromene-3',3''-oxetan]-2-yl)carbamateYield 87.4%

Reagents, catalysts & solvents 2

HCID 6505921(1E,4E)-1,5-diphenylpenta-1,4-dien-3-one; palladiumCatalystHCID 887MethanolSolvent

Conditions

Temperature
100 °C

Procedure

Under argon atmosphere, to a mixture of di-tert-butyl (6′-bromo-2′,2′-dimethyldispiro[1,3-oxazole-4,4′-chromene-3′,3″-oxetan]-2-yl)imidodicarbonate (1.00 g, 1.81 mmol), bis(dibenzylideneacetone)palladium (0) (104 mg, 0.181 mmol) and tri-tert-butylphosphonium tetrafluoroborate (53.5 mg, 0.181 mmol) was added lithium bis(trimethylsilyl)amide (1.0 M in toluene, 9.03 mL, 9.03 mmol) at ambient temperature. After stirring for 1 hour at 100° C., the reaction mixture was cooled down to ambient temperature. To the mixture were added 1.0 M hydrochloric acid (9.0 mL) and MeOH (9.0 mL) and the mixture was stirred for 30 minutes at ambient temperature. After extraction of the mixture with CHCl3, the organic layer was dried over Na2SO4 and filtered. The filtrate was concentrated at reduced pressure and the residue was purified by column chromatography on silica gel (hexane-EtOAc, a linear gradient of EtOAc from 0 to 90%) to give tert-butyl (6′-amino-2′,2′-dimethyldispiro[1,3-oxazole-4,4′-chromene-3′,3″-oxetan]-2-yl)carbamate (616 mg).

Workup

  1. temperaturethe reaction mixture was cooled down to ambient temperature
  2. stirringthe mixture was stirred for 30 minutes at ambient temperature
  3. extractionAfter extraction of the mixture with CHCl3
  4. dry with materialthe organic layer was dried over Na2SO4
  5. filtrationfiltered
  6. concentrationThe filtrate was concentrated at reduced pressure
  7. customthe residue was purified by column chromatography on silica gel (hexane-EtOAc

Sources & evidence

ORD record
ord-018297ce33cd4096b454af9f538ad4c9
Source dataset
uspto-grants-2015_03
Patent number
US08975415B2

Reaction notes

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