Trifluoroacetic acid → 7-methyl4-nitroso-3-phenyl-3,4-dihydro-2H-1,4-benzoxazine

HRID 1279705Notes

Reaction equation

HRID 1279705 reaction equation
[CH3:1][C:2]1[CH:17]=[CH:16][C:5]2[N:6]=[C:7]([C:10]3[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=3)[CH2:8][O:9][C:4]=2[CH:3]=1.FC(F)(F)C(O)=O.[N:25](OCCCC)=[O:26]>C(OCC)C>[CH3:1][C:2]1[CH:17]=[CH:16][C:5]2[N:6]([N:25]=[O:26])[CH:7]([C:10]3[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=3)[CH2:8][O:9][C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acidHCID 10996Butyl nitriteHCID 109111697-methyl-3-phenyl-2H-1,4-benzoxazine

Product 1

HCID 223363397-methyl4-nitroso-3-phenyl-3,4-dihydro-2H-1,4-benzoxazineYield 97%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
5 °C

Procedure

To a mixture of 7-methyl-3-phenyl-2H-1,4-benzoxazine (22.5 g, 99.87 mmol) in ethyl ether (300 mL) is added trifluoroacetic acid (7.7 mL, 99.87 mmol). The resulting solution is chilled to 5° C. in an ice bath and n-butyl nitrite (12.26 mL, 99.87 mmol) is added dropwise. The mixture is stirred for 1 h; solids formed during the reaction. The solids are collected by filtration and washed with ether. The filtrates are partitioned between ether and water and the organic layers are washed three times with water (500 mL), dried over magnesium sulfate, and concentrated to dryness. The combined solids gave 23.22 g (97%) of 7-methyl4-nitroso-3-phenyl-3,4-dihydro-2H-1,4-benzoxazine.

Workup

  1. customsolids formed during the reaction
  2. filtrationThe solids are collected by filtration
  3. washwashed with ether
  4. customThe filtrates are partitioned between ether and water
  5. washthe organic layers are washed three times with water (500 mL)
  6. dry with materialdried over magnesium sulfate
  7. concentrationconcentrated to dryness

Sources & evidence

ORD record
ord-905ccb680cf14deaa9383bbfbcd27cdd
Source dataset
uspto-grants-2002_09
Patent number
US06448397B1

Reaction notes

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