Hexamethylenetetramine → 3-Methyl-2-oxo-2,3-dihydro-1,3-benzoxazole-6-carbaldehyde

HRID 1271685Notes

Reaction equation

HRID 1271685 reaction equation
[CH3:1][N:2]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[O:4][C:3]1=[O:11].C1N2CN3CN(C2)CN1C3.FC(F)(F)[C:24](O)=[O:25]>>[CH3:1][N:2]1[C:6]2[CH:7]=[CH:8][C:9]([CH:24]=[O:25])=[CH:10][C:5]=2[O:4][C:3]1=[O:11]

Participants

4

Reactant 3

HCID 4101HexamethylenetetramineHCID 6422Trifluoroacetic acidHCID 308462-Benzoxazolinone, 3-methyl-

Product 1

HCID 30429773-Methyl-2-oxo-2,3-dihydro-1,3-benzoxazole-6-carbaldehydeYield 45%

Procedure

3-Methyl-3H-benzoxazol-2-one (2.0 g, 13.4 mmol) and hexamethylenetetramine (3.7 g, 26.8 mmol) were dissolved in trifluoroacetic acid (20 ml) and heated at reflux for 20 hours. The volatiles were removed in vacuo and the residue was treated with ice water (60 ml). The resultant mixture was stirred for 30 minutes and then basified with sodium carbonate. The solid was isolated by filtration, washed with water and then dried under vacuum. The solid was purified by column chromatography on silica gel eluting with an ethyl acetate and hexane solvent gradient. This provided the aldehyde as a white solid (1.07 g, 45%).

Workup

  1. temperatureheated
  2. temperatureat reflux for 20 hours
  3. customThe volatiles were removed in vacuo
  4. additionthe residue was treated with ice water (60 ml)
  5. customThe solid was isolated by filtration
  6. washwashed with water
  7. customdried under vacuum
  8. customThe solid was purified by column chromatography on silica gel eluting with an ethyl acetate and hexane solvent gradient

Sources & evidence

ORD record
ord-647bd8138a93424bb4a9976f90eb6e4d
Source dataset
uspto-grants-2007_04
Patent number
US07205408B2

Reaction notes

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