BOC-D-TYR(ME)-OH

White powder

K2CO3 (0.089 g, 0.608 mmol) was added to a solution of ester 12 (0.100 g, 0.323 mmol) in MeOH (4 ml) in presence of water (1 ml). The reaction mixture was stirred for 12h. After completion of the recation the MeOH was evaporated and the aqueous layer was extracted with EtOAc. The organic layer was dried over anhydrous Na2SO4 and then the solvent was evaporated under reduced pressure. The residue was subjected to column chromatography using ethyl acetate and petroleum ether (1:1) as eluent to yield the pure product.Boc-L-Ile-L-Pro-OBzl (1.63 g, 3.38 mmol) was dissolved in TFA (5 ml) and left with standing on ice for 30 minutes. On completion of the reaction, TFA was removed by evaporation, and the residue was vacuum-dried to obtain H-L-Ile-L-Pro-OBzl-TFA. The compound was dissolved in DMF (8 ml), and Boc-D-Tyr(Me)-OH (1.50 g, 5.07 mmol) was then added. HBTU (1.92 g, 5.07 mmol), HOBt.H2O (518 mg, 3.38 mmol), and triethylamine (2.37 ml, 16.9 mmol) were further added and stirred for three hours under ice-cooling. The reaction solution was concentrated, dissolved in ethyl acetate, and successively washed with an aqueous 10% citric acid solution, an aqueous 4% sodium bicarbonate solution, and saturated saline. The product was dried over MgSO4 and concentrated, and the resulting foam substance was purified by flash silica gel chromatography (4×30 cm, 1% methanol/chloroform) to obtain the foam title compound (1.44 g, 2.42 mmol, 72% yield). TLC: Rf=(CHCl3/MeOH=9/1).Boc-L-Ile-D-Pro-OBzl (21.5 g, 51.4 mmol) was dissolved in TFA (50 ml) and left with standing on ice for one hour. On completion of the reaction, TFA was removed by evaporation, and the residue was vacuum-dried to obtain H-L-Ile-D-Pro-OBzl-TFA. The compound was dissolved in DMF (100 ml), and Boc-D-Tyr(Me)-OH (16.7 g, 56.5 mmol) was then added. HBTU (29.4 g, 77 mmol), HOBt.H2O (7.87 g, 51 mmol), and triethylamine (25.2 ml, 180 mmol) were further added and stirred for 3 hours under ice-cooling. The reaction solution was concentrated, dissolved in ethyl acetate, and successively washed with an aqueous 10% citric acid solution, an aqueous 4% sodium bicarbonate solution, and saturated saline. The product was dried over MgSO4 and concentrated, and the resulting foam substance was purified by flash silica gel chromatography (4×30 cm, 1% methanol/chloroform) to obtain the foam title compound (22.0 g, 37 mmol, 72% yield). TLC: Rf=(CHCl3/MeOH=9/1).

Molecular Weight:295.33
XLogP3:1.8
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:5
Rotatable Bond Count:7
Exact Mass:295.14197277
Monoisotopic Mass:295.14197277
Topological Polar Surface Area:84.9
Heavy Atom Count:21
Complexity:356
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes