1,3-Cyclohexanedione → 5-methyl-1-phenyl-1,2,9,10-tetrahydro[1,4]oxazino[2,3,4-jk]carbazol-7(8H)-one

HRID 585446Notes

Reaction equation

[CH3:1][C:2]1[CH:18]=[CH:17][C:5]2[N:6](N)[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.[C:19]1(=O)[CH2:24][CH2:23][CH2:22][C:21](=[O:25])[CH2:20]1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][C:2]1[CH:18]=[C:17]2[C:5]3=[C:4]([O:9][CH2:8][CH:7]([C:10]4[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=4)[N:6]3[C:19]3[CH2:24][CH2:23][CH2:22][C:21](=[O:25])[C:20]2=3)[CH:3]=1

Participants

Conditions

Temperature: 106 °C

Procedure

To a mixture of 7-methyl-3-phenyl-2,3-dihydro-4H-1,4-benzoxazin-4-amine (5.95 g, 24.8 mmol) in toluene (175 mL) is added while stirring 1,3 cyclohexandione (2.86 g, 25.5 mmol). The mixture is heated to 95° C. for 20 min, at which time p-toluenesulfonic acid monohydrate (4.71 g, 24.8 mmol) is added and the temperature is increased to 106° C. for 1 h. The mixture is refluxed for 12 h, then cooled to room temperature and concentrated. The residue is partitioned between CH2Cl2/1N NaOH. The organic layer is washed with brine, dried over magnesium sulfate and concentrated to dryness. Column chromatography (100 g silica gel) using acetone/hexane (25/75) as eluent gave 4.06 g (51%) of 5-methyl-1-phenyl-1,2,9,10-tetrahydro[1,4]oxazino[2,3,4-jk]carbazol-7(8H)-one; mp 171° C.

Workup

additionis added
additionis added
temperatureThe mixture is refluxed for 12 h
temperaturecooled to room temperature
concentrationconcentrated
customThe residue is partitioned between CH2Cl2/1N NaOH
washThe organic layer is washed with brine
dry with materialdried over magnesium sulfate
concentrationconcentrated to dryness

Sources & evidence

ORD record: ord-0bd2c0f5d2364e8288beda486f97cd9c
Source dataset: uspto-grants-2005_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06932961B1

Reaction notes

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