Sodium Carbonate → (R)-4,6-Dimethyl-3,4-dihydro-1H-2,4a,5-triaza-fluorene-2-carboxylic Acid Tert-butyl Ester

HRID 11915

Reaction equation

HRID 11915 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:20][C@@H:19]([CH3:21])[N:18]2[C:10](=[CH:11][C:12]3[C:17]2=[N:16][C:15](Br)=[CH:14][CH:13]=3)[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[C:23](=O)([O-])[O-].[Na+].[Na+].CB1OB(C)OB(C)O1.[OH-].[Na+]>COCCOC.C1COCC1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[C:1]([O:5][C:6]([N:8]1[CH2:20][C@@H:19]([CH3:21])[N:18]2[C:10](=[CH:11][C:12]3[C:17]2=[N:16][C:15]([CH3:23])=[CH:14][CH:13]=3)[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

8

Reactant 4

HCID 10340Sodium CarbonateHCID 14798Sodium HydroxideHCID 574072TrimethylboroxineHCID 86590112(4R)-6-bromo-4-methyl-3,4-dihydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

Product 1

HCID 69357516(R)-4,6-Dimethyl-3,4-dihydro-1H-2,4a,5-triaza-fluorene-2-carboxylic Acid Tert-butyl EsterYield 71.1%

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalystHCID 8028TetrahydrofuranSolventHCID 80711,2-DimethoxyethaneSolvent

Procedure

To a solution of 0.20 g (0.55 mmol) (R)-6-bromo-4-methyl-3,4-dihydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester (Example 5, intermediate a) in 10 ml 1,2-dimethoxyethane was added 63 mg (55 μmol) tetrakis(triphenylphosphine)palladium. After 30 min, 5 ml saturated aqueous sodium carbonate solution and 0.09 ml (0.65 mmol) of a 1M trimethylboroxine solution in THF were added and the resulting suspension was heated to reflux for 5 h. The reaction mixture was cooled to room temperature, poured into 20 ml 1M aqueous sodium hydroxide solution and extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified by flash column chromatography on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (1:1) as eluant to yield the desired product as a yellow solid (71.1%).

Workup

  1. temperaturethe resulting suspension was heated
  2. temperatureto reflux for 5 h
  3. extractionextracted three times with ethyl acetate
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. customevaporated
  8. customThe residue was purified by flash column chromatography on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (1:1) as eluant

Sources & evidence

ORD record
ord-45ca063676444665b7e575b5a775cc21
Source dataset
uspto-grants-2006_08
Patent number
US07098337B2

Linked notes

Loading…