Methyl Isocyanate → 3-(n-Methylcarbamoyloxy)-5-methyl-7-tert-butyl-3h-benzofuran-2-one

HRID 2393226Notes

Reaction equation

HRID 2393226 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

5

Reactant 2

HCID 12228Methyl Isocyanate2×HCID 186202687-tert-butyl-3-hydroxy-5-methyl-3H-benzofuran-2-one2×

Product 1

HCID 226285623-(n-Methylcarbamoyloxy)-5-methyl-7-tert-butyl-3h-benzofuran-2-oneYield 65%

Reagents, catalysts & solvents 2

HCID 6395Methanesulfonic AcidCatalyst2×HCID 6344DichloromethaneSolvent

Procedure

A mixture of 5.5 g (25.0 mmol) of 7-tert-butyl-3-hydroxy-5-methyl-3H-benzofuran-2-one (compound (102), Example 2), 3 ml (50.0 mmol) of methyl isocyanate and 2 drops of methanesulfonic acid is refluxed for 31/4 hours. Then 3 ml (50.0 mmol) of methyl isocyanate and 2 drops of methanesulfonic acid are again added. The reaction mixture is refluxed for a further 16 hours, then cooled, diluted with dichloromethane and washed with water and 5% aqueous sodium hydrogencarbonate solution. 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 (112), Table 1), m.p. 138°-143° C.

Workup

  1. temperatureis refluxed for 31/4 hours
  2. temperatureThe reaction mixture is refluxed for a further 16 hours
  3. temperaturecooled
  4. washwashed with water and 5% aqueous sodium hydrogencarbonate solution
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated on a vacuum rotary evaporator
  7. customCrystallisation of the residue from toluene

Sources & evidence

ORD record
ord-99b88e4b91804cdd8e2555880ed154ef
Source dataset
uspto-grants-1998_09
Patent number
US05807505

Reaction notes

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