The Uleine Group

Uleine methiodide underwent a facile Hofmann degradation to give an optically inactive compound (CCXLVIII), which retained the two nitrogen atoms and had carbazole UV-absorption. A further Hofmann degradation eliminated Nb and gave a product (CCXLIX) with somewhat extended carbazole absorption, which underwent ready catalytic reduction with saturation of one double bond to give a substituted 

3- ethylcarbazole (CCLII) which was synthesized as follows. Ethyl 2-oxalylbutyrate and the Mannich base, ethyl-j8-dimethylaminoethyl ketone condensed to the cyclohexenone, CCLIII, which was reduced with zinc to CCLIV. The Fischer indole synthesis was then applied to this ketone and led via the phenylhydrazone, CCLV, to the tetrahydro-carbazole carboxylic acid, CCLVI, whose methyl ester, CCLVII, was dehydrogenated over palladium charcoal to l-methyl-3-ethylcarbazole (CCLII) identical with the degradation product. 

The chemistry of uleine (CCXLV) parallels that of gramme, and the methiodide (CCLVII-D) suffers facile nucleophilic attack at the benzylic 

4- position with cleavage of the C-4—N bond. Thus with methoxide 

Principal mass spectral fragments from uleine (CCXLV) 

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