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An efficient total synthesis of thalicarpine (13b), a tumor-inhibitory aporphine benzylisoquinoline alkaloid, is described. The diaryl ether (8a), prepared from lb and 4a, was condensed with the 3,4-dihydroisoquinolinium salt 2a to give 9a. Reduction of 9a, followed by diazotization in phosphoric acid and heating, yielded the aporphine 10a and the phenol 9h. Formylation of 10a gave (±)-hernandaline (10b), which was resolved with (+)-a-bromocamphor-7T-sulfonic acid. The overall yield of the hernandaline precursor 10a was improved by a reaction sequence involving the phenolic intermediates 2b, 9f, 9g, and 10c. Hernandaline (10b, S configuration) was condensed with the Reissert compound 5 and the product (12) was reduced with zinc in acetic acid to a mixture of nor bases (13a and epimer). Methylation with formalin-formic acid gave thalicarpine (13b).

The 2‐aryl‐4‐bromo‐5‐trifluoromethylpyrrole‐3‐carbonitriles represent a new class of insect control agents. The high insectidical activity observed in this series prompted us to investigate the preparation of regioisomeric arylhalotrifluoromethylpyrrole carbonitriles. The synthesis and biological activity of eight of the twelve possible regioisomers are described and discussed.

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