Boron trifluoride → 1-(2-Methyloxazol-4-yl)cyclopropanamine

2-Methyloxazole-4-carbonitrile (5 g, 46.1 mmol, 1 eq) was dissolved in dry THF at room temperature, and to which titanium(IV) isopropoxide (16 ml, 655 mmol, 1.2 eq) was added dropwise over a period of 15 minutes. The resulting mixture was stirred for 10 min and ethyl magnesium bromide (85 ml, 17 volumes) was added slowly dropwise at ambient temperature and the reaction was stirred for 1 h. Later BF3.etherate (16.7 ml, 115 mmol, 2.5 eq) was added slowly at ambient temperature and the above solution was stirred at ambient temperature for 3 h. Finally water was added and the pH was brought to 10 using 10% sodium hydroxide solution. The reaction mixture was extracted with dichloromethane, concentrated and purified by combiflash chromatography. Yield: 1.5 g (20%). 1HNMR (400 MHz, DMSO-d6): δ 0.93 (m, 2H), 1.00 (m, 2H), 1.98 (br s, 2H), 2.39 (s, 3H), 7.33 (s, 1H). LCMS: (ES+) m/z=138.9 (M+H).

1. stirringthe reaction was stirred for 1 h
2. additionetherate (16.7 ml, 115 mmol, 2.5 eq) was added slowly at ambient temperature
3. stirringthe above solution was stirred at ambient temperature for 3 h
4. extractionThe reaction mixture was extracted with dichloromethane
5. concentrationconcentrated
6. custompurified by combiflash chromatography

ORD-Eintrag

ord-4a8348f9974549a9bde6009c36a4e812

Quelldatensatz

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08722688B2