Fig. 6
From: Room temperature, metal-free, CDI-promoted, ex-situ protocol for S-methyl thioester synthesis

Synthesis of S-methyl thioesters of α-amino acids. [a] In Chamber 1 added 1.0 mmol of amino acid, 1.2 mmol of CDI, 1.0 mL of CH3CN, stirred at 30 °C (RT) for 1 h. After 1 h, in chamber 2 added 1.2 mmol of S-alkylisothiourea salt, 1.0 mL of 2 M NaOH, stirred at 30 °C (RT) for 3 h.