Reaktion #93404

Reaktionsgleichung

2-mercaptobenzothiazole

but-3-ene-1,2,3-tricarboxylic acid

H2SO4

→

4-(benzothiazol-2-ylthio)-butane-1,2,3-tricarboxylic acid

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGwith stirring
2. 2
   SonstigeThe aqueous solution is decanted from a little glutinous sediment
3. 3
   workup.ADDITIONdiluted with a further 200 ml of water
4. 4
   workup.STIRRINGAfter stirring for 1 hour
5. 5
   Filtrationthe precipitate is filtered off
6. 6
   Sonstigedried

Vorschrift

4.45 g of 2-mercaptobenzothiazole and 5 g of but-3-ene-1,2,3-tricarboxylic acid are ground together in a mortar. The powdered mixture is introduced in portions into 60 ml of 70% H2SO4 at 48°-50° in the course of 1 hour, with stirring. After a further 3 hours at 48°-50°, the reaction mixture is cooled to room temperature and diluted with 250 ml of water at 25°-30°, with stirring. The aqueous solution is decanted from a little glutinous sediment and diluted with a further 200 ml of water. After stirring for 1 hour, the precipitate is filtered off and dried. The 4-(benzothiazol-2-ylthio)-butane-1,2,3-tricarboxylic acid obtained has a melting point of 188°-190°, after recrystallisation from methanol/water.

Quelle