Dimethylformamide → HCID 131714157, compound

Participants

Reaction Steps

The DMF-containing solution of H-Ala-Val-Asp(OtBu)-Thr(tBu)-Ser(tBu)-Ser(tBu)-Glu(OtBu)-OC6H5 (~16.8 mmol) from the preceeding step was cooled to 0° and Ac-Ser(tBu)-Asp(OtBu)-Ala-OSu, VII, (10.92 g, 20.16 mm, 1.2 eq.) added. Stirring proceeded at 0° for 30 min and 25° for 17 h while the pH was maintained at ~8 by addition of Et3N. Water (2.4 L) was added with stirring and the product was collected by filtration and dried in vacuo. The solid was crushed and washed with CH3OH (3×200 mL) and dried in vacuo. Yield: 23.0 g (91.7%); mp 255°-256°; Rf 0.48 (CHCl3 :CH3OH:AcOH; 80-5-1); [α]D25 -25.60° (c 1, TFE). Anal. calc. for C73H122N10O22 (1491.86): C, 58.77; H, 8.24; N, 9.39. Found: C, 58.54; H, 8.23; N, 9.43.

Provenance & Evidence