triethylamine in water; N,N-dimethyl-formamide 16 h; Ambient temperature;

1: 75.5 percent / Et3N / H2O / Ambient temperature 2: 15.2 g / DCC / dimethylformamide / 1.) 0 deg C, 2 h; 2.) 7-8 deg C, overnight 3: 1.) NEt3; 2.) HOBt / 1.) DMF, 10 min; 2.) 7-8 deg C, overnight View Scheme

2: 61 percent / N-methylmorpholine / dimethylformamide; tetrahydrofuran / 3 h 3: 89 percent / N-methylmorpholine, HOBt, DCC / dimethylformamide / 16 h 4: 67 percent / TFMSA-thioanisole, ethanedithiol / trifluoroacetic acid / 1 h View Scheme

4-methyl-morpholine in N,N-dimethyl-formamide 40 h; Ambient temperature;