1,2-Dimethoxyethane → (4R,9aR)-6-Isobutyl-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

HRID 11943Notes

Reaction equation

HRID 11943 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]([CH2:22]O)=[CH:14][CH:13]=3)[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].COCCOC.[CH2:30]([Al](CC(C)C)CC(C)C)[CH:31](C)[CH3:32].[OH-].[Na+]>>[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]([CH2:22][CH:31]([CH3:32])[CH3:30])=[CH:14][CH:13]=3)[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 4

HCID 80711,2-DimethoxyethaneHCID 14798Sodium HydroxideHCID 16682931Triisobutylaluminum2×HCID 67238448(4R,9aR)-6-hydroxymethyl-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester2×

Product 1

HCID 69556517(4R,9aR)-6-Isobutyl-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl esterYield 76.2%

Procedure

To a solution of 2.0 g (5.43 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 50 ml 1,2-dimethoxyethane 0.75 g (0.65 mmol) tetrakis(triphenylphosphine)palladium was added. After 20 min, 16.3 ml (16.3 mmol) triisobutylaluminium (1M solution in n-hexane) was added and the reaction mixture was heated under reflux for 66 h. After cooling to room temperature another 8.1 ml (8.1 mmol) triisobutylaluminium (1M solution in n-hexane) was added and the reaction again heated under reflux. After 5 h the reaction was poured onto 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 chromatographed on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (1:3) as eluant to afford the desired compound as a light brown oil (76.2%).

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureunder reflux for 66 h
  3. additionwas added
  4. customthe reaction
  5. temperatureagain heated
  6. temperatureunder reflux
  7. extractionextracted three times with ethyl acetate
  8. washThe combined organic layers were washed with brine
  9. dry with materialdried over magnesium sulfate
  10. filtrationfiltered
  11. customevaporated
  12. customThe residue was chromatographed on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (1:3) as eluant

Sources & evidence

ORD record
ord-cb8ff8e70d0648c3ae6436d1841b5099
Source dataset
uspto-grants-2006_08
Patent number
US07098337B2

Reaction notes

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