Dimethylformamide → Boc-Leu-DTrp-betaAla-OEt

Participants

Reaction Conditions

Reaction Steps

To a solution of Boc-Leu-DTrp-NHNH2 (39 mg) obtained in Example 1-(2) in DMF (0.5 ml) was added 3.1M HCl/1,4-dioxane (81 μl ) at -60° C. The temperature of the solution was raised to -20° C. and isoamyl nitrite (15 μl ) was added. The reaction mixture was stirred at -20° C. to -15° C. for 1.5 h and cooled at -60 ° C. A solution of βAla-OEt·HCI (17 mg) in DMF (0.5 ml) and TEA (50 μl ) were added. The reaction mixture was stirred at 5° C. overnight and concentrated under reduced pressure. The residue was partitioned between water and dichloromethane. The organic layer was washed with water, dried over MgSO4, filtered, and concentrated under reduced pressure. The residue was purified by preparative TLC (Merck, Kieselgel 60 F254) with chloroform/methanol=30/1 for development to give the product (41 mg).

Provenance & Evidence