ethyl 5-broMooxazole-4-carboxylate synthesis

Yield:1097306-75-6 36.7%

Reaction Conditions:

with N-Bromosuccinimide;1,1'-azobis(1-cyanocyclohexanenitrile) in tetrachloromethane at 80;

Steps:

66.1 Step 1: Example 66b

To a solution of Example 66a (184 mg, 1.3 mmol) in CC1₄ (2 mL) was added NBS (348 mg, 1.9 mmol) and l, l'-Azobis(cyanocyclohexane) (32 mg, 0.13 mol) , the mixture was heated to 80°C overnight. The residue was extracted with EtOAc (20 mL * 2). The combined organic phase was washed with brine, dried over Na₂S0₄, filtrated and concentrated under reduced pressure to give the crude product which was further purified by silica gel chromatography to give the pure product Example 66b (105 mg, yield 36.7%)as white solid. LCMS [M+1]⁺=220.1 1HNMR (400 MHz, CDC1₃) δ 8.25 (s, 1H), 4.44 -4.35 (m, 2H), 1.38 (t, J= 7.1 Hz, 3H).

References:

WO2017/218960,2017,A1 Location in patent:Paragraph 00629