反应详情

1 g of 4-methyl-β-carbolin-3-carboxylic acid ethyl ester is dissolved in 120 ml of chloroform saturated at 0° C. with chlorine gas and stirred for 3 hours while cooling with ice. The excess chlorine and part of the chloroform are then distilled with suction in vacuo, the crystalline precipitate is filtered off, suspended in 50 ml of ethyl acetate, and aqueous ammonia (5%, 10 ml) is added thereto. After 10 minutes, the crystalline product had dissolved. After separating off the aqueous phase and washing the organic phase with water, the residue is dried with sodium sulphate, filtered, and the solvent is distilled off in vacuo. The residue is crystallized from ethyl acetate. 0.73 g of 6-chloro-4-methyl-β-carbolin-3-carboxylic acid ethyl ester of melting point 225°-228° C. is obtained.

1. temperaturewhile cooling with ice
2. distillationThe excess chlorine and part of the chloroform are then distilled with suction in vacuo
3. filtrationthe crystalline precipitate is filtered off
4. additionaqueous ammonia (5%, 10 ml) is added
5. waitAfter 10 minutes
6. dissolutionthe crystalline product had dissolved
7. customAfter separating off the aqueous phase
8. washwashing the organic phase with water
9. dry with materialthe residue is dried with sodium sulphate
10. filtrationfiltered
11. distillationthe solvent is distilled off in vacuo
12. customThe residue is crystallized from ethyl acetate