反应详情

温度

80 °C

A suspension of 2,3 -dichloro-1,4-naphthoquinone (6.83g; 0.03 mole) in methanol (40 ml) was stirred during the addition of a solution of sodium nitrite (6.9g; 0.1 mole) in water (50ml) and the mixture stirred at 80° C for 3 hours. Solution was attained after about 1 hr and the nitro naphthoquinone began to separate after 2 hrs. After cooling in ice and the yellow crystalline solid was filtered off, taken up in water (200ml), charcoalized and precipitated the product by addition of one-third the volume of concentrated hydrochloric acid, filtered off, washed well with 5N HCl and dried in vacuo over P2O5 /NaOH to give 5.30 g (81%) of material of m.p. 162°-163° C (d) which was identical to that prepared above.

1. waitSolution was attained after about 1 hr
2. customto separate after 2 hrs
3. temperatureAfter cooling in ice
4. filtrationthe yellow crystalline solid was filtered off
5. customprecipitated the product
6. additionby addition of one-third the volume of concentrated hydrochloric acid
7. filtrationfiltered off
8. washwashed well with 5N HCl
9. dry with materialdried in vacuo over P2O5 /NaOH