Methyl iodide → 5-methoxy-1-methyl-2H-3,1-benzoxazine-2,4(1H)-dione

HRID 981295Notes

Reaction equation

HRID 981295 reaction equation
[CH3:1][O:2][C:3]1[C:8]2[C:9](=[O:14])[O:10][C:11](=[O:13])[NH:12][C:7]=2[CH:6]=[CH:5][CH:4]=1.[H-].[Na+].IC.O(C(C)C)[CH:20](C)C>CN(C)C=O>[CH3:1][O:2][C:3]1[C:8]2[C:9](=[O:14])[O:10][C:11](=[O:13])[N:12]([CH3:20])[C:7]=2[CH:6]=[CH:5][CH:4]=1

Participants

6

Reactant 4

HCID 6328Methyl iodideHCID 7914Diisopropyl EtherHCID 24758Sodium hydride2×HCID 107502955-Methoxy-2H-3,1-benzoxazine-2,4(1H)-dione

Product 1

HCID 154801945-methoxy-1-methyl-2H-3,1-benzoxazine-2,4(1H)-dioneYield 80.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

To a stirred and cooled (<10° C.) solution of 9.65 parts of 5-methoxy-2H-3,1-benzoxazine-2,4(1H)-dione in 54 parts of N,N-dimethylformamide were added portionwise 2.64 parts of a sodium hydride dispersion 50%. After stirring for 1 hour in an ice bath. 7.81 parts of iodomethane were added dropwise at <15° C. When the reaction mixture was solidified, 45 parts of N,N-dimethylformamide were added and a sodium hydride dispersion 50% was further added dropwise. Upon complete addition, stirring was continued overnight while the reaction mixture was allowed to reach room temperature. The reaction mixture was poured into ice water and 2,2'-oxybispropane was added. The precipitated product was filtered off, washed with water and dried, yielding 8.37 parts (80.7%) of 5-methoxy-1-methyl-2H-3,1-benzoxazine-2,4(1H)-dione; mp. 215.8° C. (interm. 2)

Workup

  1. stirringAfter stirring for 1 hour in an ice bath
  2. additionUpon complete addition
  3. stirringstirring
  4. customto reach room temperature
  5. additionwas added
  6. filtrationThe precipitated product was filtered off
  7. washwashed with water
  8. customdried

Sources & evidence

ORD record
ord-d895623cfa69427487b16d3414c9b874
Source dataset
uspto-grants-1991_02
Patent number
US04990521

Reaction notes

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