Methanesulfonic Acid → HCID 178465174, compound

Participants

Reaction Steps

Boc-Leu-Arg(Ts)-Pro-NHEt was prepared from Boc-Arg(Ts)-Pro-NHEt obtained in Example 1 and Boc-Leu by the same procedure as Example 1. To a solution composed of the compound (0.969 g) and dichloromethane (10 ml), methanesulfonic acid (0.78 g) was added at room temperature, and the resulting mixture was stirred at room temperature for 4 hours, thereby the Boc group was removed (reaction conversion ratio: 100.0%). After the reaction, triethylamine in an amount of the same molar equivalent as that of the added methanesulfonic acid was added thereto, and the resulting mixture was stirred for 15 minutes. After Boc-D-Leu (0.40 g) and HOBt monohydrate (0.33 g) were added to the thus obtained dichloromethane solution of Leu-Arg(Ts)-Pro-NHEt, the reaction solution was cooled with ice. Then, EDC hydrochloride (0.42 g) was added thereto, and the resulting mixture was stirred for 1 hour. Subsequently, the temperature of the mixture was raised to room temperature and the mixture was stirred for 15 hours, thereby performing a condensation reaction (reaction conversion ratio: 100.0%).

Provenance & Evidence