Hydrochloric Acid → HCID 70531581, compound

To a suspension of 14.2 g of cis-1-methyl-3-phenyl-4-piperidinol, 21.4 g of triphenylphosphine, 16.3 g of hydroquinone monobenzyl ether and 375 ml of anhydrous benzene is added dropwise under nitrogen at 5° C. a solution of 14 g of diethyl azodicarboxylate in 375 ml of benzene. After the addition is complete the mixture is stirred overnight at room temperature and the precipitated solid is filtered and washed with benzene. The filtrate is concentrated in vacuo to a dark brown oil which is triturated overnight with 500 ml of hexane in a stoppered flask. The hexane is decanted and the gummy solid is triturated with a little ether. The resulting solid is filtered and washed well with ether. The combined filtrates are concentrated in vacuo, and the residue is dissolved in 750 ml of ether and extracted with 2 N hydrochloric acid (1×300 ml, 1×150 ml). The acid washings are extracted with dichloromethane (1×300 ml, 1×150 ml). The dichloromethane extracts are washed with 10% sodium hydroxide solution (300 ml), water (300 ml), and sodium chloride solution (300 ml), dried over anhydrous sodium sulfate and concentrated in vacuo to afford a brown gum. The gum is triturated with hexane, then with ether, filtered, washed with ether, and the filtrate concentrated in vacuo to afford a solid. The solid is dissolved in 500 ml of ether and treated dropwise with 20 ml of saturated ethereal hydrogen chloride. The precipitate is filtered, washed with ether, dried and recrystallized from 75 ml of absolute ethanol to afford product as nearly colorless crystals, mp 213.5°-214.5° C.

1. additionAfter the addition
2. filtrationthe precipitated solid is filtered
3. washwashed with benzene
4. concentrationThe filtrate is concentrated in vacuo to a dark brown oil which
5. customis triturated overnight with 500 ml of hexane in a stoppered flask
6. customThe hexane is decanted
7. customthe gummy solid is triturated with a little ether
8. filtrationThe resulting solid is filtered
9. washwashed well with ether
10. concentrationThe combined filtrates are concentrated in vacuo
11. dissolutionthe residue is dissolved in 750 ml of ether
12. extractionextracted with 2 N hydrochloric acid (1×300 ml, 1×150 ml)
13. extractionThe acid washings are extracted with dichloromethane (1×300 ml, 1×150 ml)
14. washThe dichloromethane extracts are washed with 10% sodium hydroxide solution (300 ml), water (300 ml), and sodium chloride solution (300 ml)
15. dry with materialdried over anhydrous sodium sulfate
16. concentrationconcentrated in vacuo
17. customto afford a brown gum
18. customThe gum is triturated with hexane
19. filtrationwith ether, filtered
20. washwashed with ether
21. concentrationthe filtrate concentrated in vacuo
22. customto afford a solid
23. filtrationThe precipitate is filtered
24. washwashed with ether
25. customdried
26. customrecrystallized from 75 ml of absolute ethanol
27. customto afford product as nearly colorless crystals, mp 213.5°-214.5° C.

ORD record

ord-4ee9f9f62362428e85b299117b752a93

Source dataset

uspto-grants-1983_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04382141