N,N,N',N'-Tetramethylazodicarboxamide → Benzoxazines

HRID 1715669Notes

Reaction equation

HRID 1715669 reaction equation
CN(C(N=NC([N:10]([CH3:12])C)=O)=O)C.[C:13]12(CS(O)(=O)=O)[C:20](C)(C)[CH:17]([CH2:18][CH2:19]1)[CH2:16][C:14]2=[O:15].O1CCCOO1>C(Cl)Cl.OS(O)(=O)=O.[O-]S([O-])(=O)=O.[Cu+2]>[O:15]1[C:14]2[CH:16]=[CH:17][CH:18]=[CH:19][C:13]=2[CH:20]=[CH:12][NH:10]1

Participants

7

Reactant 3

HCID 4278N,N,N',N'-TetramethylazodicarboxamideHCID 18462Bicyclo[2.2.1]heptane-1-methanesulfonic acid, 7,7-dimethyl-2-oxo-, (1S)-HCID 19593658CID 19593658

Product 1

HCID 17845026BenzoxazinesYield 450.6%

Reagents, catalysts & solvents 3

HCID 1118Sulfuric AcidCatalystHCID 24462Copper SulfateCatalystHCID 6344DichloromethaneSolvent

Procedure

To 6.5 g (27 mmol) of the phenolic diamide in 200 mL of anhydrous CH2Cl2 was added 6.5 g CuSO4, 2.3 g (10 mmol) camphor sulfonic acid, 36 g (400 mmol) trioxane, and 10 drops H2SO4 with rapid stirring. The resulting suspension was heated to reflux under argon atmosphere and refluxed for 72 hr. The reaction mixture as concentrated to 100 mL by simple distillation at which point no starting material was seen by TLC (EtOAc). The reaction mixture was diluted to 400 mL with CH2Cl2, and then filtered through celite. The filtrate was washed with 100 mL of 1 N NaOH, dried over Na2SO4, and concentrated in vacuo yielding 6.0 g crude benzoxazine intermediate. The crude benzoxazine was chromatographed on 200 g of silica gel (EtOAc) yielding 4.0 g (59%) of intermediate with one spot to TLC and the following property: FTIR 3327, 1664, 1641, 1552, 1428, 1329.

Workup

  1. temperatureThe resulting suspension was heated
  2. temperatureto reflux under argon atmosphere
  3. temperaturerefluxed for 72 hr
  4. concentrationThe reaction mixture as concentrated to 100 mL by simple distillation at which point no starting material
  5. additionThe reaction mixture was diluted to 400 mL with CH2Cl2
  6. filtrationfiltered through celite
  7. washThe filtrate was washed with 100 mL of 1 N NaOH
  8. dry with materialdried over Na2SO4
  9. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-9d168c92bb824577b4efab752bde7124
Source dataset
uspto-grants-2010_09
Patent number
US07799913B2

Reaction notes

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