HCID 54333393, compound → HCID 68838832, compound

Participants

Reaction Conditions

Reaction Steps

Alloc-Tyr-OH (38, 5.5 g) was dissolved in DMF (40 mL) and half the volume of DMF was removed under reduced pressure. The residue was cooled at 0° C. under a N2 atmosphere and sodium hydride (60% disperse, 1.9 g) was added in small portions. The suspension was stirred for one hour at 0° C. Then benzyl bromide (1.88 mL) in DMF (5 mL) was added. After one hour at RT 2N hydrochloric acid (7 mL) was added and the mixture concentrated under reduced pressure. To the residue H2O (50 mL) was added, the pH was adjusted to nine using 2N aq. sodium hydroxide and washed with a mixture of toluene and EtOAc. EtOAc was added and the mixture acidified to pH 3 using 2N hydrochloric acid. The organic layer was separated, dried (Na2SO4) and concentrated. The residue was purified using silica gel column chromatography (DCM/MeOH/AcOH, 89/10/1, v/v/v). The product from the column was dissolved in EtOAc, washed with H2O, dried (Na2SO4) and concentrated to give compound 39 (4.66 g, 77%). Rf 0.5 (DCM/MeOH/AcOH, 89/10/1, v/v/v).

Provenance & Evidence