Water → 2,3-Dihydro-4H-1-benzopyran-4-one O-(Methylcarbamoyl) oxime

HRID 1863437Notes

Reaction equation

HRID 1863437 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[N:11][OH:12])[CH2:3][CH2:2]1.O.[CH3:14][N:15]=[C:16]=[O:17]>C1C=CC=CC=1>[CH3:14][NH:15][C:16]([O:12][N:11]=[C:4]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:10]=2[O:1][CH2:2][CH2:3]1)=[O:17]

Participants

5

Reactant 3

HCID 962WaterHCID 12228Methyl IsocyanateHCID 44866984H-1-Benzopyran-4-one, 2,3-dihydro-, oxime

Product 1

HCID 539682462,3-Dihydro-4H-1-benzopyran-4-one O-(Methylcarbamoyl) oxime

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

A 60 g (0.37 mole) portion of 4-chromanone oxime in 770 ml of benzene was refluxed until all water was removed via a Dean-Stark trap, 0.5 hrs. The solution was cooled to 25-30°, treated with 0.5 ml of triethylamine followed by the dropwise addition of 20 ml (0.33 mole) of methyl isocyanate at less than 70°. The reaction mixture was refluxed for 3 hrs., stored at room temperature overnight, filtered, and stripped of benzene under reduced pressure. The residue was treated with 200 ml of ether, cooled 20 min. and filtered. The white crystalline product was washed with 100 ml of ether and dried, m.p. 123°-126°. Yield: 64 g (88%).

Workup

  1. customwas removed via a Dean-Stark trap, 0.5 hrs
  2. temperatureThe solution was cooled to 25-30°
  3. additiontreated with 0.5 ml of triethylamine
  4. temperatureThe reaction mixture was refluxed for 3 hrs
  5. filtrationfiltered
  6. additionThe residue was treated with 200 ml of ether
  7. temperaturecooled 20 min.
  8. filtrationfiltered
  9. washThe white crystalline product was washed with 100 ml of ether
  10. customdried

Sources & evidence

ORD record
ord-fc6f2a96da7049a181d4a8683aa25f7c
Source dataset
uspto-grants-1979_09
Patent number
US04169097

Reaction notes

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