4-Methylmorpholine → HCID 131714443, compound

Participants

Reaction Conditions

Reaction Steps

3.48 ml (3.18 g=31.5 m mol) N-methylmorpholine and 1.86 ml (1.8 g=15.0 m mol) pivaloyl chloride are added to a solution of 6.65 g (15.0 m mol) BOC-(D)-Ala-MeLeu-Me-Leu-OH in 60 ml chloroform, pre-cooled to -20° C. Conversion to the anhydride is completed after stirring for 2 hours at -20° C. (IR control). 3.35 g (15.0 m mol) H-MeVal-Bzl in 50 ml chloroform are then added dropwise to the reaction mixture at -20° C. The progress of the reaction is followed by means of thin-layer chromatography and IR-spectrometry and is complete after 41/2 days. The obtained solution is poured onto 200 ml 1N sodium bicarbonate on a shaker, and diluted with 300 ml chloroform. After separation of the organic phase, the aqueous phase is extracted with a further 100 ml chloroform, the combined chloroform phases dried over sodium sulphate, filtered and evaporated. The residue is chromatographed on 600 g silica gel (0.063-0.2 mm) using 2% methanol in methylene chloride as eluant to yield the title compound: rotation, [α]D25 =-143.7° (c=0.9 in chloroform).

Provenance & Evidence