Supplier Page from Thermo Fisher Scientific for O-[(Ethoxycarbonyl)cyanomethylenamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate, 97%
2-Ethoxyethyl ether, 98+%, extra pure from Thermo Fisher Scientific
4-Fluoroaniline, 98% from Thermo Fisher Scientific
Ethyl butyrate, 99% from Thermo Fisher Scientific