Reaction #417941

Reaction equation

NaHCO3

methyl 3-amino-4-hydroxybenzoate

methyl 4-formylbenzoate

DDQ

→

compound 1

Yield 86.0%

3,4-diamino-benzoic acid ethyl ester

Yield 86.0%

Solvents

methanol

Conditions

Workup

1. 1
   OtherThe solvent was evaporated under reduced pressure
2. 2
   workup.DISSOLUTIONthe remaining residue was dissolved in dichloromethane (150 mL)
3. 3
   workup.STIRRINGthe reaction mixture was stirred at rt for 1 h
4. 4
   FiltrationThe suspension was filtered off
5. 5
   Washthe resulting solid was washed with saturated NaHCO3 (50 mL), water (50 mL), and ethyl acetate (100 mL)
6. 6
   Otherdried in vacuo

Procedure

A mixture of methyl 3-amino-4-hydroxybenzoate (2.5 g, 15 mmol) and methyl 4-formylbenzoate (2.46 g, 15 mmol) in methanol (75 mL) was stirred at rt overnight. The solvent was evaporated under reduced pressure and the remaining residue was dissolved in dichloromethane (150 mL). DDQ (3.5 g, 15.4 mmol) was added and the reaction mixture was stirred at rt for 1 h. Saturated NaHCO3 (200 mL) was added. The suspension was filtered off, the resulting solid was washed with saturated NaHCO3 (50 mL), water (50 mL), and ethyl acetate (100 mL) and dried in vacuo to give compound 1 (4 g, 86% yield) as yellow solid.

Source