berberrubine(2).[7,8]The structure of the latter was established from it sphysical and spectral(1HNMRandMS) properties.
Berberine(1)contains two methoxy group sinits D-ringat C-9 and C-10.Under microwave irradiation the selective demethylation of the
C-9 methoxy group resulted in the formation of berberrubine(2).