Hydrochloric Acid → Carbamic acid, [(2R)-2-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-2-hydroxyethyl]-, 1,1-dimethylethyl ester

HRID 901571Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 901571
B.CSC.CB1N2CCC[C@@H]2C(C2C=CC=CC=2)(C2C=CC=CC=2)O1.[CH3:26][C:27]1([CH3:48])[O:32][C:31]2[CH:33]=[CH:34][C:35]([C:37](=[O:47])[CH2:38][NH:39][C:40](=[O:46])[O:41][C:42]([CH3:45])([CH3:44])[CH3:43])=[CH:36][C:30]=2[CH2:29][O:28]1.Cl>C1COCC1.C1(C)C=CC=CC=1>[CH3:26][C:27]1([CH3:48])[O:32][C:31]2[CH:33]=[CH:34][C:35]([C@@H:37]([OH:47])[CH2:38][NH:39][C:40](=[O:46])[O:41][C:42]([CH3:44])([CH3:43])[CH3:45])=[CH:36][C:30]=2[CH2:29][O:28]1

Komponenten

7

Edukt 4

HCID 313Hydrochloric AcidHCID 9838490(R)-2-Methyl-CBS-oxazaborolidineHCID 10870948Carbamic acid, [2-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-2-oxoethyl]-, 1,1-dimethylethyl esterHCID 12423031(Dimethyl sulfide)trihydroboron2×

Produkt 1

HCID 10881838Carbamic acid, [(2R)-2-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-2-hydroxyethyl]-, 1,1-dimethylethyl esterAusbeute 85,7 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 1140TolueneLösungsmittelHCID 8028TetrahydrofuranLösungsmittel3×

Versuchsvorschrift

A 2M solution of borane—dimethyl sulphide in THF (28 ml) was added slowly to a 1M solution of (R)-tetrahydro-1-methyl-3,3-diphenyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaborole in toluene (56 ml) at 0° under nitrogen. A solution of tert-butyl 2-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)-2-oxoethylcarbamate, (108.2 g) in THF (1.3 litres) was added slowly keeping the temperature below 5° followed by 2M solution of borane—dimethyl sulphide in THF (252 ml) over 50 min. After 1 h, 2M HCl (170 ml) was added with cooling and the mixture was partitioned between EtOAc and water. The organic layer was washed with saturated NaHCO3 solution and brine and dried (MgSO4). The solution was concentrated and the product purified by chromatography on flash silica gel (800 g), eluting successively with hexane:EtOAc (4:1 then 3:1) to give the title compound (93.3 g), LCMS RT=3.31 min.

Aufarbeitung

  1. customthe temperature below 5°
  2. temperaturewith cooling
  3. customthe mixture was partitioned between EtOAc and water
  4. washThe organic layer was washed with saturated NaHCO3 solution and brine
  5. dry with materialdried (MgSO4)
  6. concentrationThe solution was concentrated
  7. customthe product purified by chromatography on flash silica gel (800 g)
  8. washeluting successively with hexane:EtOAc (4:1

Quellen und Nachweise

ORD-Eintrag
ord-aeec6744817249eda8e7b131fa4e4910
Quelldatensatz
uspto-grants-2008_04
Patentnummer
US07361787B2

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