Benzoic Acid → Methyl Benzoate

HRID 601437Notes

Reaction equation

HRID 601437 reaction equation
[OH-].[K+].[CH3:3]N(N=O)S(C1C=CC(C)=CC=1)(=O)=O.[N+](=C)=[N-].[C:20]([OH:28])(=[O:27])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1>CS(C)=O.CN(C=O)C>[C:20]([O:28][CH3:3])(=[O:27])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

7

Reactant 4

HCID 243Benzoic AcidHCID 6628DiazaldHCID 9550Diazomethane2×HCID 14797Potassium Hydroxide2×

Product 1

HCID 7150Methyl Benzoate

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 6228DimethylformamideSolvent

Procedure

In a 1.5 l double-walled glass reactor 531 g of aqueous 30% KOH solution are submitted and are heated, respectively, to 40° C., 55° C. and 70° C. By controlled dropwise addition of 405.8 g of 26.4% N-methyl-N-nitroso-p-toluenesulfonamide (MNTSA) solution in DMSO into this KOH solution, diazomethane (DAM) is generated and is aspirated in gaseous form into a glass reactor via a frit by means of vacuum at 500 mbar. The metered addition is effected in such a way that the diazomethane concentration in the gas phase does not exceed a partial pressure of 120 mbar. With a view to determining the DAM quantity and yield, this glass reactor is charged with an acid, for example with a solution of benzoic acid in DMF, so that the DAM aspirated via the frit reacts to completion immediately to form methyl benzoate, and the content thereof is determined analytically and can be utilized as an equivalent for DAM. The following table reproduces the results:

Workup

  1. temperatureare heated
  2. customto 40° C.
  3. custom55° C. and 70° C
  4. customis aspirated in gaseous form into a glass reactor via a frit by means of vacuum at 500 mbar
  5. additionThe metered addition
  6. concentrationthat the diazomethane concentration in the gas phase
  7. customyield
  8. customreacts to completion immediately

Sources & evidence

ORD record
ord-586df830b9e249a6a59f332590c9c69f
Source dataset
uspto-grants-2011_03
Patent number
US07902342B2

Reaction notes

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