Water → (4R,9aR)-6-Ethyl-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic Acid Tert-butyl Ester

HRID 11916

Reaction equation

HRID 11916 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:20][C@@H:19]([CH3:21])[N:18]2[C@H:10]([CH2:11][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].[CH2:23](B(CC)CC)[CH3:24].C(=O)([O-])[O-].[K+].[K+].O>CN(C)C=O.C1COCC1.Cl[Pd]Cl.C1(P(C2C=CC=CC=2)[C-]2C=CC=C2)C=CC=CC=1.[C-]1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=C1.[Fe+2]>[C:1]([O:5][C:6]([N:8]1[CH2:20][C@@H:19]([CH3:21])[N:18]2[C@H:10]([CH2:11][C:12]3[C:17]2=[N:16][C:15]([CH2:23][CH3:24])=[CH:14][CH:13]=3)[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

8

Reactant 4

HCID 962WaterHCID 7357Triethylborane2×HCID 11430Potassium CarbonateHCID 86590113(4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester2×

Product 1

HCID 69359739(4R,9aR)-6-Ethyl-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic Acid Tert-butyl EsterYield 89.5%

Reagents, catalysts & solvents 3

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 6228DimethylformamideSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 0.70 g (1.90 mmol) (4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester (Example 5, intermediate b) in 14 ml N,N-dimethylformamide was added 73.0 mg [1,1′-bis(diphenyphosphino)ferrocene]-dichloropalladium(II) and after 15 min, 4.8 ml of a 1M triethylborane solution in THF and 0.79 g (5.70 mmol) potassium carbonate were added. After 4 h another 2.4 ml triethylborane solution was added and the reaction mixture stirred overnight at 65 deg C. The mixture was cooled to room temperature and the suspension was poured into water and extracted twice with ethyl acetate. The combined organic phases were washed with brine, dried over magnesium sulfate, filtered and evaporated. The crude product was purified by column chromatography on silica gel (Q0.032–0.063 mm) with tert-butyl methyl ether:n-hexane (1:4) as eluant to yield the product as a colorless oil (89.5%).

Workup

  1. extractionextracted twice with ethyl acetate
  2. washThe combined organic phases were washed with brine
  3. dry with materialdried over magnesium sulfate
  4. filtrationfiltered
  5. customevaporated
  6. customThe crude product was purified by column chromatography on silica gel (Q0.032–0.063 mm) with tert-butyl methyl ether:n-hexane (1:4) as eluant

Sources & evidence

ORD record
ord-e401693ea07b49d8b2d0052599bf9d7b
Source dataset
uspto-grants-2006_08
Patent number
US07098337B2

Linked notes

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