[OH:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[C:11]([CH3:18])[O:10][N:9]=2)=[CH:4][CH:3]=1.C([O-])([O-])=O.[Cs+].[Cs+].[CH2:25](Br)[CH:26]=[CH2:27].O>C1COCC1.C(OCC)(=O)C>[CH2:27]([O:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[C:11]([CH3:18])[O:10][N:9]=2)=[CH:6][CH:7]=1)[CH:26]=[CH2:25]The mixture of ethyl 3-(4-hydroxyphenyl)-5-methylisoxazole-4-carboxylate (Preparation C) (0.474 g, 1.92 mmol), Cs2CO3 (0.937 g, 2.88 mmol) and allyl bromide (0.27 mL, 3.12 mmol) in 10 mL of THF was sealed in a 150-mL pressure vessel and stirred at 90° C. overnight. The reaction mixture was cooled to room temperature. Water (150 mL) and ethyl acetate (150 mL) were added to the reaction mixture. Layers were separated and the aqueous layer was extracted with ethyl acetate (150 mL). The combined organic extract was dried over anhydrous sodium sulfate. Solvent was evaporated in vacuo to give 0.66 g of crude product, which was used in the next step without purification. LCMS (method B) RT 3.34 min., MH+288. 1H NMR (500 MHz, CDCl3) δ 7.58 (d, J=8.5Hz, 2H), 6.96 (d, J=8.5Hz, 2H), 6.12-6.00 (m, 1H), 5.46-5.26 (m, 2H), 4.58 (d, J=5.2Hz, 2H), 4.25 (q, J=7.2Hz, 2H), 2.71 (s, 3H), 1.25 (t, J=7.2 Hz, 3H).
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