Boron trifluoride → 1-(Pyrimidin-5-yl)cyclopropan-1-amine

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Reaction Steps

5-Cyano pyrimidine (5 g, 47.6 mmol, 1 eq) was taken in a Dry THF under Argon atmosphere, then Titanium isopropoxide (17 ml, 57.1 mmol, 1.2 eq) was added slowly at ambient temperature and the resulting mass was stirred for 15 mins. To the above stirred solution was added Ethyl magnesium bromide (1 M solution in THF, 107 ml, 809.3 mmol, 2.5 eq) slowly via syringe at ambient temperature. (During the addition of EtMgBr reaction mass turned black). Then the reaction mass was stirred for an hour, BF3.EtO (16.7 ml, 119.0 mmol, 2.5 eq) was added slowly through syringe at 0° C. Then the reaction was allowed to attain ambient temperature and the stirring was continued for another one hour. Finally the reaction was quenched by adding 50 ml of water and the reaction mass was passed through Celite and the bed was washed with water and Ethyl acetate. The filtrate was basified with 10% NaOH solution (pH=9) and then extracted with DCM and washed with brine solution. The required product was purified by silica gel (60-120) column chromatography using DCM/methanol as the eluent. Yield: 0.1 g (5%) 1H NMR (400 MHz, DMSO-d6): 1.04-1.08 (q, 2H, J=3.96 Hz), 1.18-1.25 (q, 2H, J=3.96 Hz), 8.26 (d, 2H), 9.05 (s, 1H). LCMS: (ES+) m/z=136 (M+H).

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