With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.19932-85-5,6-Bromobenzo[d]oxazol-2(3H)-one,as a common compound, the synthetic route is as follows.,19932-85-5
The bromo compound R (1.0 g, 4.67 mmol) was taken in an oven-dried RB equipped with magnetic stir-bar and dissolved in anhydrous THF (9 mL). The solution was cooled to -78 C. and MeMgBr (1.8 mL) was added slowly. The mixture was stirred for 45 min and anhydrous THF (37.5 mL) was added slowly to maintain the internal temperature at -50 C. After the solution was cooled back to -78 C., t-BuLi (10.6 mL, 9.8 mmol, 1.6 M in pentane) was added dropwise. Next, DMF (2.2 mL, 28.1 mmol) was added slowly to the yellow solution and the dry-ice bath was removed after 15 min. After 2 h, the reaction was quenched with water and the THF was removed under vacuo on a rotary evaporator. The residue was dissolved in ethyl acetate and washed with 1N HCl (5 mL). The organic layer was separated and the aqueous layer was extracted with ethyl acetate (3¡Á5 mL). The organic layers were combined, dried over Na2SO4 and concentrated under vacuo on a rotary evaporator. The crude was first recrystallized from hexanes/ethyl acetate and then purified via gradient silica gel column chromatography using a mixture of hexanes and ethyl acetate (10:1 to 1:1) to obtain the desired aldehyde S as a white solid (500 mg, 66%). 1H NMR (500 MHz, CDCl3): delta 9.85 (s, 1H), 7.66 (dd, J=7.9 Hz, 1.2 Hz, 1H), 7.63 (s, 1H), 7.11 (d, J=7.9 Hz, 1H). 13C NMR (125 MHz, CDCl3): delta 190.9, 155.2, 144.1, 135.9, 131.4, 128.2, 109.6, 109.5
As the paragraph descriping shows that 19932-85-5 is playing an increasingly important role.
Reference£º
Patent; DUTTA, Aloke K.; US2014/309427; (2014); A1;,
Benzoxazole – Wikipedia
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