Methyl Isocyanate → 3-(n-Methylcarbamoyloxy)-5-methyl-7-tert-butyl-3h-benzofuran-2-one
Reaction equation
[C:1]([C:5]1[C:13]2[O:12][C:11](=[O:14])[CH:10]([OH:15])[C:9]=2[CH:8]=[C:7]([CH3:16])[CH:6]=1)([CH3:4])([CH3:3])[CH3:2].[CH3:17][N:18]=[C:19]=[O:20]>CS(O)(=O)=O.ClCCl>[CH3:17][NH:18][C:19]([O:15][CH:10]1[C:9]2[CH:8]=[C:7]([CH3:16])[CH:6]=[C:5]([C:1]([CH3:4])([CH3:3])[CH3:2])[C:13]=2[O:12][C:11]1=[O:14])=[O:20]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
A mixture of 5.5 g (25.0 mmol) of 7-tert-butyl-3-hydroxy-5-methyl-3H-benzofuran-2-one (compound (202), Example 1a), 3 ml (50.0 mmol) of methyl isocyanate and 2 drops of methanesulfonic acid are refluxed for 31/4 hours. Then a further 3 ml (50.0 mmol) of methyl isocyanate and 2 drops of methanesulfonic acid are added. The reaction mixture is refluxed for another 16 hours, then cooled, diluted with dichloromethane and washed with water and a 5% aqueous solution of sodium hydrogencarbonate. The organic phases are combined, dried over magnesium sulfate and concentrated on a vacuum rotary evaporator. Crystallisation of the residue from toluene yields 4.45 g (65%) of 3-(N-methylcarbamoyloxy)-5-methyl-7-tert-butyl-3H-benzofuran-2-one (compound (212), Table 2), m.p. 138°-143° C. (compound (212), Table 2).
Workup
- temperatureare refluxed for 31/4 hours
- temperatureThe reaction mixture is refluxed for another 16 hours
- temperaturecooled
- washwashed with water
- dry with materialdried over magnesium sulfate
- concentrationconcentrated on a vacuum rotary evaporator
- customCrystallisation of the residue from toluene
Sources & evidence
- ORD record
- ord-c026d9804f304106af431211f3aed51c
- Source dataset
- uspto-grants-1996_05
- Patent number
- US05516920
Reaction notes
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