A 10 mL microwave reaction vessel was charged with 4′-bromo-1′-methyl-3,7-dihydro-2H-spiro[benzofuro[5,6-b][1,4]dioxine-8,3′-indolin]-2′-one (0.19 g, 0.5 mmol), 4-methoxyphenol (0.12 g, 1.0 mmol), potassium tert-butoxide (0.11 g, 1.0 mmol), copper (I) bromide (0.012 g, 0.08 mmol) and anhydrous 1-methylpyrrolidin-2-one (2 mL). The reaction mixture was irradiated at 250° C. for 75 min in a microwave reactor and was allowed to cool to ambient temperature. The reaction mixture was poured into water (15 mL) and extracted with ethyl acetate (50 mL). The combined organic extracts were washed with water (3×50 mL) and brine (50 mL), dried over magnesium sulfate, filtered and concentrated in vacuo. Purification of the residue by column chromatography and eluted with a 15% to 50% gradient of ethyl acetate in hexanes afforded 4′-(4-methoxyphenoxy)-1′-methyl-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-2′(1′H)-one (0.084 g, 39%) as an off-white solid: mp 55-58° C. (ethyl acetate/hexanes); 1H NMR (300 MHz, CDCl3) δ7.27-7.14 (m, 1H), 6.78-6.59 (m, 5H), 6.44 (d, J=8.48 Hz, 1H), 6.31 (d, J=1.08 Hz, 1H), 6.22 (d, J=1.08 Hz, 1H), 4.86 (ABq, 2H), 4.16-4.03 (m, 4H), 3.74 (s, 3H), 3.26 (s, 3H); 13C NMR (75 MHz, CDCl3) δ177.6, 155.8, 155.6, 154.3, 149.6, 144.8, 144.3, 137.7, 130.0, 120.2, 120.1, 119.5, 114.5, 112.7, 111.0, 103.1, 99.1, 64.4, 63.9, 57.4, 55.6, 27.0; MS (ES+) m/z 432.0 (M+1).
