反应详情

21.2 g of 1,3-benzodioxane-6,7-diamine was dissolved while heating in 300 ml of alcohol, then diluted with 75 ml of water, treated with 23.6 g of potassium ethylxanthate and boiled under reflux overnight. Subsequently, there were added thereto 300 ml of water and at 60°-70° C. 20 ml of glacial acetic acid. After stirring at this temperature for 1 hour, the suspension was cooled, suction filtered and washed with water. 21.6 g (81.2% of theory) of 1,8-dihydro-m-dioxino(5,4-f)benzimidazole-2-thiol of melting point 288°-289° C. were obtained.

1. temperatureunder reflux overnight
2. additionSubsequently, there were added
3. customat 60°-70° C
4. temperaturethe suspension was cooled
5. filtrationsuction filtered
6. washwashed with water