反应详情

温度

200 °C

A mixture of 5.2 g of the product of Step A and 10.4 g of pyridinium hydrochloride was heated at 200° C. for 21/2 hours and the mixture was cooled and diluted with water. Ammonium hydroxide was added to the mixture which was then extracted with methylene chloride. The organic phase was washed with water, dried and evaporated to dryness under reduced pressure. The residue was chromatographed over silica gel and was eluted with a 6-3-1 cyclohexane-chloroform-triethylamine mixture to obtain 3.95 g of 3-(1-ethyl-1,2,5,6-tetrahydropyridin-3-yl)-phenol. 3.85 g of the latter were dissolved in 40 ml of isopropanol and 2.4 g of oxalic acid were added thereto. The mixture was cooled and filtered and the product was washed with isopropanol and dried to obtain 3.57 g of 3-(1-ethyl-1,2,5,6-tetrahydropyridin-3-yl)-phenol oxalate melting at 240° C.

1. temperaturethe mixture was cooled
2. extractionwas then extracted with methylene chloride
3. washThe organic phase was washed with water
4. customdried
5. customevaporated to dryness under reduced pressure
6. customThe residue was chromatographed over silica gel
7. washwas eluted with a 6-3-1 cyclohexane-chloroform-triethylamine mixture