p-Toluenesulfonic acid → 2,2,3,3-Tetramethyl-1,4-diazaspiro[4.5]decane

HRID 1584009Notes

Reaction equation

HRID 1584009 reaction equation
Cl.Cl.[NH2:3][C:4]([CH3:10])([C:6]([NH2:9])([CH3:8])[CH3:7])[CH3:5].[OH-].[Na+].[C:13]1(=O)[CH2:18][CH2:17][CH2:16][CH2:15][CH2:14]1.C1(C)C=CC(S(O)(=O)=O)=CC=1>O.C1C=CC=CC=1>[CH3:5][C:4]1([CH3:10])[C:6]([CH3:8])([CH3:7])[NH:9][C:13]2([CH2:18][CH2:17][CH2:16][CH2:15][CH2:14]2)[NH:3]1

Participants

7

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 7967CyclohexanoneHCID 14798Sodium HydroxideHCID 187604952,3-Dimethylbutane-2,3-diamine--hydrogen chloride (1/2)

Product 1

HCID 202577522,2,3,3-Tetramethyl-1,4-diazaspiro[4.5]decane

Reagents, catalysts & solvents 2

HCID 241BenzeneSolventHCID 962WaterSolvent

Procedure

2,3-Diamino-2,3-dimethylbutane dihydrochloride is neutralized with aqueous caustic soda and the diamine is recovered. The wet diamine (15.3 grams) is then heated with benzene (150 mls) to azeotrope off about 2.2 mls of water. The benzene, containing 13.1 grams (0.113 mole) of the diamine, is then treated with cyclohexanone (11.0 grams 0.112 mole) and p-toluenesulfonic acid (50 mgs) and the reaction mixture is refluxed for 40 hours in a flask fitted with a Dean-Stark water separator. The benzene is then removed by distillation and the reddish liquid residue is fractionally distilled. The main fraction, b.p 82°-84° C. at 1 mm pressure, has a nuclear magnetic resonance spectrum identical to that reported in the literature [Keana et al., J. Am. Chem. Soc. 100, pg. 934 (1978)]. On standing the liquid solidifies to a crystalline solid, m.p. 31°-32° C., which contains 9.95% water.

Workup

  1. customthe diamine is recovered
  2. temperatureThe wet diamine (15.3 grams) is then heated with benzene (150 mls)
  3. temperaturethe reaction mixture is refluxed for 40 hours in a flask
  4. customThe benzene is then removed by distillation
  5. distillationthe reddish liquid residue is fractionally distilled
  6. customThe main fraction, b.p 82°-84° C.

Sources & evidence

ORD record
ord-490b25066a1c4e17aff7c6d8e09fc07c
Source dataset
uspto-grants-1985_11
Patent number
US04555537

Reaction notes

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