Benzyl chloroformate → HCID 18512823, compound

Participants

Reaction Steps

To D6 (0.500 g, 1.30 mmol) and DBU (794 mg, 5.21 mmol) in refluxing methanol (100 ml) was added neat benzylchloroformate and the reaction refluxed for 3 hours until complete conversion of D6 to either the protected amino acid D19 or its methyl ester was observed. The solvent was removed and the residues taken up into dioxane (60 ml) and water (2 ml) and lithium hydroxide (1 g) added. The reaction was then refluxed for 2 hours until hydrolysis of the methyl ester derivative to D19 was complete. The solvent was removed, the residues suspended in 1M HCl (100 ml) and extracted with hot ethyl acetate (300 ml). The hot ethyl acetate was dried (MgSO4) and the solvent volume reduced to 40 ml. The solution/suspension was left at −10° C. for 1 hour, allowed to warm to room temperature and the resulting white precipitates filtered off and dried under vacuum to yield the title compound (585 mg, 87%). M.Pt 102-104° C. C32H55NO4 requires 517.4. Found ES−: MCI−, 552.6. δH (d6DMSO), 1.32 (38H, s, (CH2)19(CH2)2N), 1.52 (2H, p, CH2CH2CO2H), 1.65 (2H, p, CH2CH2NH), 2.35 (2H, t, CH2CO2H), 3.18 (2H, t, CH2N), 5.14 (2H, s, CH2Ph), 7.35 (5H, m, Ph).

Provenance & Evidence