| Abstract: | 1,5-Dimethylbenzothieno[2,3-g]isoquinoline (thiaolivacine) has been prepared from the nitro-vinyl derivative of 4-methyl-3-dibenzothiophenecarboxaldehyde. Using the same aldehyde, 4-des-methylisothiaolivacine was prepared by formation of the Schiff's base with aminoacetaldehyde diethyl acetal followed by cyclization. Similar methods yielded the pyrido-N-isomer, 1-des-methylthiaolivacine, from 4-methyl-2-dibenzothiophenecarboxaldehyde. The thiaolivacine parent unsubstituted ring system, benzothieno[2,3-g]isoquinoline, was prepared from 2-dibenzothio-pheneearboxaldehyde by the aminoacetaldehyde approach, as was the corresponding oxygen analog, benzofuro[2,3-g]isoquinoline, from 2-dibenzofurancarboxaldehyde. The 100 MHz spectra of these fused isoquinolines are recorded and correlated. |
