1: 3-amino-4-hydroxy benzoic acid With sodium carbonate in water T=45°C; 2: methyl chloroformate in water T=45 - 80°C; 3: With hydrogenchloride in water pH=2 - 3; Cooling with ice;

sodium hydroxide

T=150°C;

potassium hydroxide in ethanol 4 h; Ambient temperature;