反应详情

A suspension of 2.5 g of 6-chloro-1'-cyano-1-(2-nitrophenyl)spiro[indoline-3,4'-piperidine], Example 31, in 40 ml of 3N hydrochloric acid and 20 ml of glacial acetic acid is refluxed for 16 hours under nitrogen. Thereafter, the mixture is permitted to cool before sequentially being basified with dilute sodium hydroxide and extracted with ether. The combined ether extracts are successively washed with water, dried and concentrated under vacuum leaving an oil residue. The residue, in ether, is converted to its maleic acid salt which is recrystallized from an acetone-ether mixture to provide orange prisms, mp 153°-155° C. of 6-chloro-1-(2-nitrophenyl)spiro[indoline-3,4'-piperidine] maleate.

1. temperatureto cool
2. extractionextracted with ether
3. washThe combined ether extracts are successively washed with water
4. customdried
5. concentrationconcentrated under vacuum
6. customleaving an oil residue
7. customis recrystallized from an acetone-ether mixture