Reaction #903

Reaction equation

CO2

dimethyl sulfate

sodium

2-methyl-3-nitro-6-aminobenzoic acid

sodium hydrogen carbonate

2-methyl-3-nitro-6-aminobenzoic acid

→

Methyl 2-methyl-3-nitro-6-aminobenzoate

Solvents

acetone

water

acetone

Conditions

Workup

1. 1
   TemperatureThe mixture is then heated
2. 2
   Otherthus obtained
3. 3
   Temperaturethe mixture is subsequently refluxed for a further three hours
4. 4
   Temperatureto cool
5. 5
   Extractionis extracted with methylene chloride
6. 6
   OtherAfter drying the organic phase, it
7. 7
   Concentrationis concentrated
8. 8
   OtherThe solid obtained
9. 9
   Otheris sufficiently pure for the subsequent reaction (NMR)

Procedure

49.7 g (0.253 mol) of 2-methyl-3-nitro-6-aminobenzoic acid are dissolved in 380 ml of acetone and 43 g (0.51 mol) of sodium hydrogen carbonate are added. The mixture is then heated to boiling until evolution of CO2 is complete. 35.3 g (0.28 mol) of dimethyl sulfate are then added dropwise in the course of two hours at the boiling point of acetone to the suspension of the sodium salt of 2-methyl-3-nitro-6-aminobenzoic acid thus obtained, and the mixture is subsequently refluxed for a further three hours and then allowed to cool. After pouring the reaction mixture into 1.8 l of water, it is extracted with methylene chloride. After drying the organic phase, it is concentrated. The solid obtained is sufficiently pure for the subsequent reaction (NMR).

Source