1-Hydroxybenzotriazole → HCID 57936733, compound

Participants

Reaction Steps

17.0 g H-D-Trp-Lys(BOC)-OMe are mixed with 80 ml THF. 9.2 g Z-Phg-OH are added to the grey suspension at RT. Addition of 4.4 g HOBt, rinsing with 20 ml THF. The turbid yellow solution is cooled down to 0° and a solution of 5.3 ml DICI in 15 ml THF added within 10 minutes. Stirring 2 hours at 0°, then 2 hours at RT. Then addition of a solution of 3.6 sulfuric acid in 57 ml water, extraction with 70 ml ethyl acetate, washing with water, saturated brine, 5% sodium hydrogencarbonate, 25% brine, drying over MgSO4 and evaporation. The white residue is stirred in 125 ml isopropyl acetate 2 hours at 40° and the suspension filtered. Drying of the residue at 40°: slightly yellow substance. HPLC: 96.3% b.a. (25.3 min).

Provenance & Evidence