chloroformic acid ethyl ester; triethylamine in acetone T=0 - 30°C;

1: 2-methoxy-4-amino-5-ethylsulphonyl benzoic acid With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride in dichloromethane T=0°C; 0.5 h; 2: 1-ethyl-2-aminomethylpyrrolidine hydrochloride With triethylamine in dichloromethane T=20°C;

in triethylamine; acetone

triethylamine in water; acetone

1.1: bromine / methanol / 5 - 15 °C / Industry scale 2.1: sodium sulfide / water; acetone / 5 - 15 °C / Industry scale 3.1: sodium hydroxide; water / methanol / 65 °C / Industry scale 3.2: 5 - 10 °C / pH 4 - 4.5 / Industry scale 4.1: dihydrogen peroxide / sodium tungstate / water; methanol / 5 h / 20 - 30 °C 5.1: chloroformic acid ethyl ester; triethylamine / acetone / 0 - 30 °C View Scheme

1.1: potassium hydroxide; tetrabutylammomium bromide / acetone / 1 h / 25 - 35 °C / Industry scale 2.1: bromine / methanol / 5 - 15 °C / Industry scale 3.1: sodium sulfide / water; acetone / 5 - 15 °C / Industry scale 4.1: sodium hydroxide; water / methanol / 65 °C / Industry scale 4.2: 5 - 10 °C / pH 4 - 4.5 / Industry scale 5.1: dihydrogen peroxide / sodium tungstate / water; methanol / 5 h / 20 - 30 °C 6.1: chloroformic acid ethyl ester; triethylamine / acetone / 0 - 30 °C View Scheme

1.1: sodium sulfide / water; acetone / 5 - 15 °C / Industry scale 2.1: sodium hydroxide; water / methanol / 65 °C / Industry scale 2.2: 5 - 10 °C / pH 4 - 4.5 / Industry scale 3.1: dihydrogen peroxide / sodium tungstate / water; methanol / 5 h / 20 - 30 °C 4.1: chloroformic acid ethyl ester; triethylamine / acetone / 0 - 30 °C View Scheme

1.1: sodium hydroxide; water / methanol / 65 °C / Industry scale 1.2: 5 - 10 °C / pH 4 - 4.5 / Industry scale 2.1: dihydrogen peroxide / sodium tungstate / water; methanol / 5 h / 20 - 30 °C 3.1: chloroformic acid ethyl ester; triethylamine / acetone / 0 - 30 °C View Scheme