3,4-DIHYDRO--CARBOLINES: II. THE EXHAUSTIVE METHYLATION OF 3,4-DIHYDRO--CARBOLINE

The methiodide of 3,4-dihydro-β-carboline yields a dimeric anhydro base which, on heating, disproportionates to a β-carboline and a tetrahydro-β-carboline derivative, and on methylation is converted to 3-[2-formylindolyl]-β-ethyltrimethylamnionium iodide.