Benzyl Bromide → 1-Benzyl-4-iodo-1H-pyrazole

A 250-mL round-bottomed flask was charged with 4-iodo-1H-pyrazole (17 g, 87.63 mmol, 1.00 equiv) in N,N-dimethylformamide (150 mL) To this was added sodium hydride (3.6 g, 105.00 mmol, 1.20 equiv, 70%) in several batches at 0° C., followed by addition of 1-(bromomethyl)benzene (16.5 g, 96.49 mmol, 1.10 equiv) dropwise at 0° C. The resulting solution was allowed to warm up to room temperature and stirred for 2 hours at room temperature. The reaction was then quenched by the addition of water/ice (200 mL). The resulting solution was extracted with ethyl acetate (3×200 mL). Combined organic layers were dried over anhydrous sodium sulfate, filtered off and concentrated on a rotary evaporator affording 1-benzyl-4-iodo-1H-pyrazole as yellow solid (22 g, 80%).

1. customThe reaction was then quenched by the addition of water/ice (200 mL)
2. extractionThe resulting solution was extracted with ethyl acetate (3×200 mL)
3. dry with materialCombined organic layers were dried over anhydrous sodium sulfate
4. filtrationfiltered off
5. concentrationconcentrated on a rotary evaporator

ORD record

ord-ad35016e52a548d7a4384f913021dddd

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08080566B1