Reaktion #62863

Reaktionsgleichung

HCl

Na2CO3

2,5-dichloro-4-methyl-3-nitrobenzoic acid

Na2S2O4

→

3-Amino-2,5-dichloro-4-methylbenzoic acid

Lösungsmittel

glycol monomethyl ether

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solid which has precipitated
2. 2
   Sonstigeis isolated
3. 3
   Sonstigedried

Vorschrift

43 g of 2,5-dichloro-4-methyl-3-nitrobenzoic acid and 108.8 g of Na2S2O4 are boiled in a mixture of 340 ml of glycol monomethyl ether and 340 ml of water for 3 hours. 480 ml of 1/2-concentrated HCl are added to the still warm solution and the mixture is then boiled up once again. After cooling to room temperature, the mixture is poured into 1 l of ice-water and the strongly acid solution is buffered with Na2CO3 (pH 5). The solid which has precipitated is isolated and dried. Melting point: 218°-21°, yield: 32.5 g.

Quelle