反应详情

To a stirred mixture of 2-chloro-4-methyl-6-nitroaniline (7.39 g, 39.7 mM) and concentrated sulfuric acid (6.2 mL) in absolute ethanol (50 mL) at 0°-5° C. was slowly added a solution of sodium nitrite (6.85 g, 99.3 mM) in water (6 mL). The temperature of the reaction mixture was not allowed to exceed 5° C. during the addition. After the addition was completed, the reaction mixture was stirred at room temperature for 0.5 hr and then at reflux until the evolution of gas from the reaction mixture ceased. The reaction mixture was allowed to cool and was concentrated. The residue was slurried with ether and then filtered to remove the solids. The filtrate was concentrated and the residue chromatographed (eluant: diethyl ether/hexane; 1/9) to provide (6.25 g, 92%) the title compound as a yellow crystalline solid, mp 60.5-61° C.; MS(CI): 172 (M+H).

1. additionto exceed 5° C. during the addition
2. additionAfter the addition
3. temperatureat reflux until the evolution of gas from the reaction mixture
4. temperatureto cool
5. concentrationwas concentrated
6. filtrationfiltered
7. customto remove the solids
8. concentrationThe filtrate was concentrated
9. customthe residue chromatographed (eluant: diethyl ether/hexane; 1/9)