Diisopropylethylamine → N-Boc-2-Methyl-Piperidine

N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (0.46 g, 2.42 mmol) and 1-hydroxy-benzotriazole monohydrate(0.37 g, 2.41 mmol) were added to a solution of 2-methylpiperidine-1,4-dicarboxylic acid-1-tert-butylester (0.59 g, 2.42 mmol) in N,N-dimethylformamide (8 mL). After 30 min at 20° C. a solution of (2R)-2-amino-N-methyl-N-[(1R)-1-(3-methyl-1,2,4-oxadiazol-5-yl)-2-(2-naphthyl)ethyl]-3-(2-naphthyl)propionamide (as a trifluoroacetate) (1.0 g, 1.73 mmol) and diisopropylethylamine (0.22 g, 1.73 mmol) in N,N-dimethylformamide (4 mL) was added. After 18 h at 20° C. the reaction mixture was poured on water (100 mL) and extracted several times with ethyl acetate (total 60 mL). The collected organic phases were washed with aqueous citric acid (10%, 20 mL), a saturated solution of sodium hydrogen carbonate (20 mL) and water (3×20 mL). After drying (magnesium sulfate) the solution was concentrated in vacuo to give 1.25 g of crude 4-(1-{methyl-[1-(3-methyl-1,2,4-oxadiazol-5-yl)-2-(2-naphthyl)ethyl]carbamoyl}-2-(2-naphthyl)ethyl)-carbamoyl)-2-methylpiperidine-1-carboxylic acid tert-butyl ester that was used for the next step without further purification.

1. additionAfter 18 h at 20° C. the reaction mixture was poured on water (100 mL)
2. extractionextracted several times with ethyl acetate (total 60 mL)
3. washThe collected organic phases were washed with aqueous citric acid (10%, 20 mL)
4. dry with materialAfter drying (magnesium sulfate) the solution
5. concentrationwas concentrated in vacuo

ORD record

ord-c9fe4e1fea6a446091a1e879be175ae5

Source dataset

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06555570B2