Water → 1-(Propan-2-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

In a sealed tube, to a suspension of 4-(4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (566.9 mg, 2.922 mmol) and Cs2CO3 (1.5442 g, 4.739 mmol) in DMF (6 mL), isopropyl iodide (753.3 mg, 4.431 mmol) was added and the reaction was allowed to stir at 100° C. for 19 h. Water was added to dilute the reaction and dissolve all salts that had formed, after which EtOAc was added and the two layers were separated. The organic layer was washed twice with water and once with brine, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The combined aqueous layers were back extracted once with EtOAc, which was combined with the other organic batch. One obtained the title material as yellow oil. It was used without further purification in the next step. 1H NMR (400 MHz, CDCl3): δ=1.33 (s, 12H), 1.51 (d, J=6.8 Hz, 6H), 4.53 (spt, J=6.7 Hz, 1H), 7.75 (s, 1H), 7.80 (s, 1H). MS (AP+): m/z 235.98 (76) [MH+]. HPLC: tR=3.22 min (ZQ3, polar—5 min).

Provenance & Evidence