1190861-43-8

1190861-47-2

1190861-43-8

Tert-butyl 6-bromo-2-oxo-2',3',5',6'-tetrahydrospiro[dihydroindole-3,4'-pyran]-1-carboxylate (4.20 g, 11.0 mmol) was used as a starting material, which was dissolved in 1,4-dioxane (25 mL), and 5 M hydrogen chloride solution was added. The reaction mixture was stirred at room temperature for 5 hours. Upon completion of the reaction, the mixture was concentrated under vacuum to afford 6-bromospiro[1H-indole-3,4'-oxahexan]-2-one (3.20 g, 98% yield), the product was a light pink solid. The product was detected by LRMS at m/z 278/280 (M-1)+. 1H-NMR (DMSO-d6) δ: 1.71 (m, 4H), 3.81 (m, 2H), 4.01 (m, 2H), 6.98 (d, J=1.65 Hz, 1H), 7.14 (dd, J=7.97 Hz, J=1.65 Hz, 1H). 7.47 (d, J=7.97Hz, 1H), 10.55 (s, NH).