Diisopropylethylamine → N-[[1-(2-methoxyethyl)cyclopentyl]carbonyl]-4-(1,3,6-trimethyl-2,4-dioxo-5-pyrimidinyl)-L-phenylalanine methyl ester

To a suspension of 4-(1,3,6-trimethyl-2,4-dioxo-5-pyrimidinyl)-L-phenylalanine methyl ester hydrochloride salt (0.4 mmol, 173 mg), HBTU (0.5 mmol, 189 mg) and 1-(2-methoxyethyl)cyclopentane carboxylic acid (0.5 mmol, 86 mg) in DMF (2 mL) was added diisopropylethylamine (1.2 mmol, 0.29 mL) at room temperature. After 5 min, everything went into solution and the clear yellow solution was stirred for 24 h at room temperature. The resulting dark-brown solution was diluted with ethyl acetate (30 mL). The ethyl acetate layer was washed successively with 1N hydrochloric acid (2×30 mL), saturated sodium bicarbonate solution (30 mL), and brine solution (30 mL) and was dried over anhydrous magnesium sulfate. Filtration of the drying agent and concentration of the solvent gave the crude product which was purified by silica gel column chromatography using a Biotage (40m) column to afford 139 mg (72% yield) of N-[[1-(2-methoxyethyl)cyclopentyl]carbonyl]-4-(1,3,6-trimethyl-2,4-dioxo-5-pyrimidinyl)-L-phenylalanine methyl ester as an amorphous white solid. FAB-HRMS m/e calcd for C26H35N3O6 (M+H) 486.2604, found 486.2602.

1. washThe ethyl acetate layer was washed successively with 1N hydrochloric acid (2×30 mL), saturated sodium bicarbonate solution (30 mL), and brine solution (30 mL)
2. dry with materialwas dried over anhydrous magnesium sulfate
3. filtrationFiltration of the drying agent and concentration of the solvent
4. customgave the crude product which
5. customwas purified by silica gel column chromatography

ORD record

ord-d4075a564657429ea1993c8740503ca0

Source dataset

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06380387B1