Maximum quantity allowed is 999
We are proud to present the amidation using 2-chloro-1-methylpyridinium iodide called as Mukaiyama condensation reagent. 2-Chloro-1-methylpyridinium iodide is known to cause less racemization.
Boc-Pro-OH (1.65 g, 7.65 mmol), 2-chloro-1-methylpyridinium iodide (1.95 g, 7.65 mmol) were added to solution of H-Phe-OMe･HCl (1.50 g，6.95 mmol) in dichloromethane (30 mL) at room temperature and triethylamine (3.40 mL, 24.3 mmol) was added dropwise in 3 min at 5 to 10 °C. After stirring for 3 h, solvent was removed under reduced pressure and the residue was dissolved in ethyl acetate and washed with 10% citric acid aq. (30 mL × 3), 5% sodium bicarbonate solution aq. (30 mL × 3) and brine (30 mL). The organic layer was dried over anhydrous sodium sulfate and filtered. After the removal of solvent under reduced pressure, the given crude was purified by column chromatography (hexane : EtOAc = 2 : 1) to give Boc-Pro-Phe-OMe (2.37 g，91%) as a slightly yellowish solid.
Consumption of stating material and formation of product was monitored by LCMS.
Boc-Pro-Phe-OMe
1H NMR (400 MHz, DMSO-d6); δ 8.17–8.27 (m, 1H), 7.19–7.29 (m, 5H), 4.42–4.53 (m, 1H), 4.00–4.13 (m, 1H), 3.56–3.61 (m, 3H), 3.18–3.38 (m, 2H), 2.90–3.08 (m, 2H), 1.91–2.11 (m, 1H), 1.56–1.71 (m, 3H), 1.15-1.40 (m, 9H).
