Z-Gln-ONp → Z-Gln-Thr(tBu)-Ala-Ile-Gly-OMe

Participants

Reaction Steps

4.6 g of the H-Thr(tBu)-Ala-Ile-Gly-OMe described under 28) in 30 ml of dimethylformamide, are mixed with 3.5 g of Z-Gln-ONP and stirred at room temperature until the mixture becomes solid. After allowing to stand overnight the mixture is diluted with ether and the precipitate is filtered off and washed with ether until free of nitrophenol. The protected pentapeptide shows Rf = 0.14 in the system chloroform-methanol (95:5) in a thin layer chromatogram on silica gel. Melting point: > 250° C.

Provenance & Evidence