反应详情

Into a 500-mL 3-necked round-bottom flask, purged and maintained with an inert atmosphere of nitrogen, was placed a solution of methylmagnesium bromide (3 M in THF) (63.4 mL, 190 mmol) in THF (100 mL) A solution of 4-bromopyridine-2-carbonitrile (11.6 g, 63.4 mmol; patent US 2009/0239876 A1, example 2) in THF (40 mL) was added drop-wise at room temperature over 40 min. Methanol (40 mL) was then added drop-wise followed by portion-wise addition of sodium borohydride (11.8 g, 312 mmol) in several batches. The resulting mixture was stirred at room temperature for 2 h, then diluted with ethyl acetate (200 mL). The pH of the mixture was adjusted to 9 with aqueous sodium hydroxide (1 M) and the solids were removed by filtration. The filtrate was extracted with ethyl acetate (2×100 mL) and the combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to yield 10.3 g (crude) of the title compound as a yellow oil.

1. customInto a 500-mL 3-necked round-bottom flask, purged
2. temperaturemaintained with an inert atmosphere of nitrogen
3. additionwas added drop-wise at room temperature over 40 min
4. customthe solids were removed by filtration
5. extractionThe filtrate was extracted with ethyl acetate (2×100 mL)
6. dry with materialthe combined organic layers were dried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure