in DMF and stirred for 5 min. This solution was added to the resin and the amide coupling was performed for 18 h. Subsequently, the resin was washed with DMF (5 × 5 mL) and CH2Cl2 (10 × 5 mL) and the completion of the reaction was confirmed via TNBS test, conducted according to manufacturer´s protocol, and by HPLC analysis after test cleavage. The modified resin was dried in vacuo.