反应详情

Perchloric acid (3 ml) was added to a hot solution of 2-(n-pentadecyl)indole-5-carboxylic acid in glacial acetic acid (60 ml) and the mixture was hydrogenated at normal pressure using palladium on charcoal (5% w/w, 0.7 g) as catalyst. After 3.5 hours the hot mixture was filtered and the residue was washed with hot glacial acetic acid (30 ml). The pH of the combined filtrates was adjusted to 6 with 10% w/v sodium hydroxide solution. The mixture was extracted with diethyl ether (2×75 ml) and the ether solution was dried over magnesium sulphate. The solution was treated with a saturated solution of hydrogen chloride gas in ethanol to precipitate the hydrochloride. The solid was collected and recrystallised from isopropanol to give (RS)-2-(n-pentadecyl)indoline-5-carboxylic acid hydrochloride (5.6 g) as a white solid, m.p. 165°-170° C. with decomposition.

1. filtrationAfter 3.5 hours the hot mixture was filtered
2. washthe residue was washed with hot glacial acetic acid (30 ml)
3. extractionThe mixture was extracted with diethyl ether (2×75 ml)
4. dry with materialthe ether solution was dried over magnesium sulphate
5. additionThe solution was treated with a saturated solution of hydrogen chloride gas in ethanol
6. customto precipitate the hydrochloride
7. customThe solid was collected
8. customrecrystallised from isopropanol