259886-51-6

496-46-8

462-95-3

80262-44-8

259886-51-6

259886-49-2

259886-50-5

General procedure for the synthesis of cucurbit[n]uril from glyburide and diethoxymethane: Unsubstituted glyburide (19.94 g) and pure methanesulfonic acid (82 mL) were added to a reaction flask and heated to 80 °C. Subsequently, diethoxymethane (35.21 mL) was added slowly and the reaction mixture was warmed up to 100 °C (internal temperature) and kept for 18 hours. Upon completion of the reaction, the mixture was cooled and poured into acetone (410 mL) and a brown powder was precipitated. The product composition was analyzed by 1H NMR to give cucurbit[5]uril (8%), cucurbit[6]uril (42%), cucurbit[7]uril (43%), cucurbit[8]uril (7%), cucurbit[9]uril (0%), cucurbit[10]uril (0%) and cucurbit[13]uril (0%). In addition, the residual formaldehyde content was 34 ppm by HPLC.