Ethylenic heterocyclic cpds - from corresp methyl cpds and schiff's bases

摘要

Prepn. of heterocyclic compounds contg. an ethylenic double bond by reacting a cpd. of the formula (where R1 is an opt. substd. heterocyclic ring system of aromatic character which (a) contains or consists of at least one 5- or 6-membered heterocyclic ring with at least one ring N-atom, (b) is free from H-atoms which are linked to ring N-atoms and are replaceable by alkali metal, and (c) is linked through one of its ring members to a ring-member of R2 or is linked through 2 of its adjacent ring-members to 2 adjacent ring-members of R2; and R2 is an opt. subst. 5- or 6-membered carbocyclic ring with aromatic character to which one or more further aromatic, heteroaromatic or hydroaromatic rings are opt. fused; the methyl group indicated in the formula being in the p-position to a linkage between R2 and R1) with a Schiff's base in the presence of of a strongly basic alkali cpd.; there being used as reaction medium a strongly polar, neutral to basic organic solvent which (i) is free from atoms which are replaceable by alkali metal and (ii) is practically anhydrous (althrough when the strongly basic alkali compound is an alkali hydroxide this may have a water content of up to 25 wt.%). The products are useful as intermediates, e.g. for dyes or pharmaceuticals. Certain of the products, when they contain chromophoric groups, are useful as optical brighteners or as scintillators for various photographic purposes.