反应详情

20 g (49.5 mmol) of 2-hydroxyethyl isopropyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)pyridine-3,5-dicarboxylate were introduced into a mixture of 83 ml of 96% strength nitric acid in 660 ml of water and heated to boiling for 1 hour. The mixture was then cooled down to 5° to 10° C. and made weakly alkaline with dilute sodium hydroxide solution. The oil which had separated out was extracted with methylene chloride, the extracts were dried over sodium sulphate and evaporated in vacuo. The oily residue was induced to crystallize by trituration with ether/petroleum ether, filtered off with suction and recrystallized from methanol.

1. temperatureheated
2. temperatureThe mixture was then cooled down to 5° to 10° C.
3. customThe oil which had separated out
4. extractionwas extracted with methylene chloride
5. dry with materialthe extracts were dried over sodium sulphate
6. customevaporated in vacuo
7. customto crystallize by trituration with ether/petroleum ether
8. filtrationfiltered off with suction
9. customrecrystallized from methanol