4-Methylmorpholine → t-Butoxycarbonylvalyltyrosine methyl ester

Temperature

-70 °C

21.7 g of t-butoxycarbonylvaline is dissolved in 200 ml of methylene chloride. 22.2 ml of N-methylmorpholine is added to the solution. The solution is cooled to -70° C. 13.1 ml of isobutylchloroformate is then added. The reaction mixture is again cooled to -70° C. 23.2 g of tyrosine methyl ester hydrochloride is added to the reaction mixture. The reaction mixture is allowed to warm to room temperature, and then is stirred for 16 hours. The reaction mixture is extracted three times with 0.5 M potassium bisulfate and once with brine. The methylene chloride solution is dried over anhydrous sodium sulfate, filtered and stripped of solvent. The residue is dissolved in 200 ml of ethyl ether. The ether solution is added to cold rapidly stirring Skellysolve B. The white precipitate is filtered and dried to afford the product t-butoxycarbonylvalyltyrosine methyl ester.

1. temperatureThe reaction mixture is again cooled to -70° C
2. temperatureto warm to room temperature
3. extractionThe reaction mixture is extracted three times with 0.5 M potassium bisulfate
4. dry with materialThe methylene chloride solution is dried over anhydrous sodium sulfate
5. filtrationfiltered
6. dissolutionThe residue is dissolved in 200 ml of ethyl ether
7. additionThe ether solution is added to cold rapidly stirring Skellysolve B
8. filtrationThe white precipitate is filtered
9. customdried

ORD record

ord-2273e8eb9ebd41a58e68eaeaf23ea4ac

Source dataset

uspto-grants-1980_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04204991