L-Hydroxyproline → trans-4-Hydroxy-1-(4-nitrobenzyloxycarbonyl)-L-proline

6.55 g of trans-4-hydroxy-L-proline and 7.5 ml of triethylamine were dissolved in 15 ml of water, and a solution of 15.95 g of S-p-nitrobenzyloxycarbonyl-4,6-dimethyl-2-mercaptopyrimidine in 35 ml of dioxane was added thereto dropwise. The resulting mixture was stirred at room temperature for 1.5 hours and allowed to stand overnight. To the reaction mixture was added 30 ml of a 2N sodium hydroxide aqueous solution under ice-cooling, and the resulting mixture was extracted with diethyl ether. The ethereal layer was washed with 20 ml of a 1N sodium hydroxide aqueous solution and combined with the alkaline aqueous layer. The combined mixture was made acidic with 100 ml of a 2N hydrochloric acid aqueous solution and extracted with ethyl acetate. The ethyl acetate layer was washed with a 2N aqueous solution of hydrochloric acid, dried over sodium sulfate and distilled off to remove the solvent. The resulting crude crystals were washed with warm ethyl acetate to obtain trans-1-(p-nitrobenzyloxycarbonyl)-4-hydroxy-L-proline.

1. waitto stand overnight
2. temperaturecooling
3. extractionthe resulting mixture was extracted with diethyl ether
4. washThe ethereal layer was washed with 20 ml of a 1N sodium hydroxide aqueous solution
5. extractionextracted with ethyl acetate
6. washThe ethyl acetate layer was washed with a 2N aqueous solution of hydrochloric acid
7. dry with materialdried over sodium sulfate
8. distillationdistilled off
9. customto remove the solvent
10. washThe resulting crude crystals were washed with warm ethyl acetate

ORD-Eintrag

ord-dc262ca5963a4a378845f72932c746ef

Quelldatensatz

uspto-grants-1992_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05122604