Diisopropylethylamine → Methyl 1-(methylcarbamoyl)cyclopropane-1-carboxylate

1-(Methoxycarbonyl)cyclopropanecarboxylic acid 5a (2.5 g, 13.9 mmol, prepared by a known method disclosed in “Tetrahedron Letters, 1987, 28 (36), 4225-4228”) was dissolved in 20 mL of N,N-dimethylformamide, followed by addition of methylamine hydrochloride (1.4 g, 20.8 mmol), N,N-diisopropylethylamine (5.4 g, 41.7 mmol) and 2-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (7.9 g, 20.8 mmol), and then the reaction solution was stirred for 3 h. 50 mL of saturated sodium bicarbonate solution were added, and the reaction solution was extracted with ethyl acetate (40 mL×3). The organic phases were combined, washed with saturated sodium bicarbonate solution, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography with elution system A to obtain the title product methyl 1-(methylcarbamoyl)cyclopropanecarboxylate 5b (700 mg, a colorless oil) in 32% yield.

1. extractionthe reaction solution was extracted with ethyl acetate (40 mL×3)
2. washwashed with saturated sodium bicarbonate solution
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationthe filtrate was concentrated under reduced pressure
6. customThe resulting residue was purified by silica gel column chromatography with elution system

ORD record

ord-065dff7021ac46d7b132c773722c244c

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09388133B2