中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
9H-吡啶[3,4-b]吲哚 | Betacarboline | 244-63-3 | C11H8N2 | 168.198 |
—— | Norharman-2-oxide | 24223-07-2 | C11H8N2O | 184.197 |
The triethyloxonium tetrafluoroborate/1,2-dimethoxyethane (TEO/DME) mixture is a versatile and cheap substitute for trimethyloxonium tetrafluoroborate in O-methylations of pyrrolin-2-ones, quinolones, acridones, and 1-oxo-β -carbolines. Undesired O-ethylation can be avoided by preincubation of triethyloxonium tetrafluoroborate and 1,2-dimethoxyethane for 1 h, prior to addition of the substrate. In the course of these investigations it was found that the structures assigned to the alkaloids taraxacine A and B are erroneous.