Dimethylformamide → BOC-L-Met-L-Leu-OMe

Temperatur

0 °C

6.225 g. (25 mole) of BOC-L-Met was dissolved in 160 ml. of degassed dimethylformamide and cooled under nitrogen to 0° C. 4.55 g. (25 mmole) of L-Leu-OMe was dissolved in 80 ml. of dimethylformamide and set aside. To the BOC-L-Met was added 5.38 ml. of diphenylphosphorylazide in 10% excess followed by 3.48 ml. of triethylamine in 10% excess, followed by the L-Leu-OMe. The reaction mixture was stirred at 0° C. for 3 hrs., then at room temperature for 16 hrs. The solution was concentrated and treated with 3:1 dimethylformamide/water and mixed bed resin, whereupon it crystallized out on the resin. The resin and crystals were filtered and the resin washed with dimethylformamide to isolate the product. The filtrate was then concentrated and recrystallized from ethyl acetate/hexane. 7.74 g. of product was obtained.

1. wait, then at room temperature for 16 hrs
2. concentrationThe solution was concentrated
3. additiontreated with 3:1 dimethylformamide/water
4. additionmixed bed resin
5. customwhereupon it crystallized out on the resin
6. filtrationThe resin and crystals were filtered
7. washthe resin washed with dimethylformamide
8. customto isolate the product
9. concentrationThe filtrate was then concentrated
10. customrecrystallized from ethyl acetate/hexane
11. customof product was obtained

ORD-Eintrag

ord-e822de6bebed4095a9a2165aa1c7d0a9

Quelldatensatz

uspto-grants-1983_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04377515