4-Methylmorpholine → BOC-Thr-Cys(MBzl)-Thr-ol

Participants

Reaction Conditions

Reaction Steps

5.9 ml chloroformic acid isobutyl-ester are added drop-wise to a solution of 9.7 g Boc-Thr-OH and 9.4 ml N-methyl-morpholine in 50 ml THF pre-cooled to -25° C. The solution is stirred for 5 min. at -15° C. and a solution of 20 g H-Cys(MBzl)-Thr-ol trifluoroacetate and 9.8 ml N-methylmorpholine in 50 ml THF, pre-cooled to -10° C. are added. The reaction mixture is stirred for 2 hrs. at 0° C., and for 2 hrs. at room temperature. 20 ml 10% KHCO3 are added and the mixture concentrated under vacuum. The product is diluted with AcOEt and washed with 2 N citric acid, 10% KHCO3 solution and then 30% NaCl solution. The AcOEt phase is dried over Na2SO4 and evaporated under vacuum, and the residue re-crystallised from MeOH/AcOEt/hexane. The title compound is obtained after further filtration, washing with ether and drying:

Provenance & Evidence