3-Chloro-5-nitrobenzene-1,2-diamine synthesis

Yield:-

Reaction Conditions:

Stage #1: 5-chloro-2,4-dinitroanilinewith sodiumsulfide nonahydrate;ammonium chloride;sulfur in ethanol;water at 65; for 0.5 h;Inert atmosphere;
Stage #2: with water;sodium hydroxide in ethanol; for 0.5 h;

Steps:

1 Example 1 Preparation of 4-chloro-2-(7-chloro-5-nitro-1H-benzimidazol-2-yl)phenol

Under a nitrogen atmosphere, sodium sulfate nonahydrate (0.96 g, 10 mmol) was added to a solution of sulfur (0.13 g, 0.5 mmol) in water (4 ml) and anhydrous ethanol (1 ml), and the mixture was refluxed for 1 hour. The reaction solution was added to a mixed solution of 2,4-dinitro-5-chloroaniline (0.9 g, 4.1 mmol), ammonium chloride (0.21 g, 3.9 mmol) in water (4 ml) and anhydrous ethanol (7 ml). Heat to 65 ° C and stir the reaction for 30 minutes. Add 2 NaOH (4 ml), react for 30 minutes, and add IN HC1 (8 ml). The mixture was separated by adding water (20 ml) and ethyl acetate (40 ml), and the organic layer was dried over anhydrous sodium sulfate and filtered and concentrated to give the crude 3-chloro-5-nitro-1,2-phenylenediamine (0.7 g). In the next step.

References:

CN109081813,2018,A Location in patent:Paragraph 0056; 0058