Formaldehyde → 2-Acetyl-3,8-dimethyl-8-azabicyclo[3.2.1]oct-2-ene

HRID 1975821Notes

Reaction equation

HRID 1975821 reaction equation
[C:1]([C:4]1[CH:5]2[NH:12][CH:8]([CH2:9][C:10]=1[CH3:11])[CH2:7][CH2:6]2)(=[O:3])[CH3:2].C=O.[C:15]([BH3-])#N.[Na+].[OH-].[NH4+]>C(#N)C.C(O)(=O)C>[C:1]([C:4]1[CH:5]2[N:12]([CH3:15])[CH:8]([CH2:9][C:10]=1[CH3:11])[CH2:7][CH2:6]2)(=[O:3])[CH3:2]

Participants

7

Reactant 4

HCID 712FormaldehydeHCID 14923Ammonium HydroxideHCID 5003444Sodium cyanoborohydrideHCID 197513562-Acetyl-3-methyl-8-azabicyclo[3.2.1]oct-2-ene

Product 1

HCID 190988202-Acetyl-3,8-dimethyl-8-azabicyclo[3.2.1]oct-2-ene

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 6342AcetonitrileSolvent

Procedure

To a stirred mixture of 2-acetyl-3-methyl-8-azabicyclo [3.2.1]oct-2-ene (1,2083 g, 0.0073 mol) and aqueous formaldehyde (2.7 ml, 0.036 mol, 37 percent) in 15 ml acetonitrile was added sodium cyanoborohydride (0.7352 g, 0.0117 mol). After stirring for 15 minutes, the reaction was made acidic by addition of 15 ml glacial acetic acid over a 45 minute period. The solution was made basic by the addition of an aqueous solution of ammonium hydroxide. The basic solution was extracted 3 times with ethyl acetate, the organic layer was then dried using sodium sulfate and concentrated under reduced pressure. Purification on silica gel column chromatography using 9 parts diethyl ether and 1 part triethylamine followed by bulb-to-bulb distillation (80° C. 0.4 mmHg)) to give 2-acetyl-3,8-dimethyl-8-azabicyclo[3.2.1]oct-2-ene as a brownish liquid.

Workup

  1. extractionThe basic solution was extracted 3 times with ethyl acetate
  2. customthe organic layer was then dried
  3. concentrationconcentrated under reduced pressure
  4. customPurification on silica gel column chromatography
  5. distillationfollowed by bulb-to-bulb distillation (80° C. 0.4 mmHg))

Sources & evidence

ORD record
ord-7d822a1cb7fa41b0ae51e3dca314592b
Source dataset
uspto-grants-1994_02
Patent number
US05288872

Reaction notes

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