Reaktion #676437
ord-51d3039d1e7240c6b17fad1eab348526
Reaktionsgleichung
Reagenzien
Reaktionsbedingungen
Vorschrift
The dipeptide Ser-Trp was synthesized according to standard peptide technology. In a first step Z-Ser-OH and Trp-OMe were coupled via the carbonic anhydride methodology (J. Am. Chem. Soc. 1967, 5012) to yield the protected dipetide Z-Ser-Trp-OMe. To that end Trp-OMe.HCl was suspended in tetrahydrofuran (THF) and subsequently N-methylmorpholine (NMM) was added. The mixture was stirred for one hour and subsequently added to a solution of Z-Ser in tetrahydrofuran/dimethylformamide (THF/DMF). A second equivalent of NMM was added and the mixture was cooled to −15° C. Isobutyl chloroformate is added at such a rate that the internal temperature does not exceed −15° C. Subsequently, the mixture was stirred for 3 hours, the temperature was allowed to rise to ambient temperature and the precipitated NMM.HCl was removed by filtration. The filtrate was kept at 4° C. overnight after which any additional precipitate was filtered and the filtrate is concentrated in vacuo. The residue was purified by column chromatography (SiO2, ethyl acetate/heptane). The combined fractions were concentrated, washed with water to remove any remaining DMF and concentrated in vacuo.