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

HRID 11946Notes

Reaction equation

HRID 11946 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].C([Li])(C)(C)C.[CH:28](=[O:30])[CH3:29].[Cl-].[NH4+]>C(OCC)C>[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]([CH:28]([OH:30])[CH3:29])=[CH:14][CH:13]=3)[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 4

HCID 177AcetaldehydeHCID 25517Ammonium ChlorideHCID 86590113(4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl esterHCID 178418306HCID 178418306, compound

Product 1

HCID 67237860(4R,9aR)-6-(1-(RS)-Hydroxy-ethyl)-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

A solution of 6.0 g (16.3 mmol) (4R,9aR)-6-bromo-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester in 250 ml diethyl ether was cooled to −100 deg C. and treated with 11.9 ml (17.9 mmol) tert-butyllithium (1.5 M in n-pentane). After 15 min, 1.0 ml (0.79 g, 17.9 mmol) acetaldehyde was added and the reaction was stirred for 40 min at the same temperature. After warming to −75 deg C. the reaction mixture was poured onto 10% aqueous ammonium chloride 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 (2:3) as eluant to afford a first batch of compound. The remaining product-containing fractions were pooled and chromatographed again to yield a second batch of compound (56.9% total).

Workup

  1. temperatureAfter warming to −75 deg C
  2. extractionextracted three times with ethyl acetate
  3. washThe combined organic layers were washed with brine
  4. dry with materialdried over magnesium sulfate
  5. filtrationfiltered
  6. customevaporated
  7. customThe residue was chromatographed on silica gel (0.032–0.063 mm) with ethyl acetate:n-hexane (2:3) as eluant
  8. customto afford a first batch of compound
  9. additionThe remaining product-containing fractions
  10. customchromatographed again
  11. customto yield a second batch of compound (56.9% total)

Sources & evidence

ORD record
ord-b99a44cabbc54b1fb8e18ab7df58ee0d
Source dataset
uspto-grants-2006_08
Patent number
US07098337B2

Reaction notes

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