Arynes quinolines from

From the addition reactions of phthalic anhydride with pyridine, naphthalene was formed in much greater quantity than quinoline isoquinoline was either totally absent or present in only minute amounts. These facts indicated (a) if there were much 1,2-addition of benzyne, it occurred predominantly at the 1,2 and 3,4 atoms in pyridine (b) 1,4-addition took place at carbon atoms in preference to a nitrogen and a carbon atom. Studies with other systems indicate that arynes have a decided preference for 1,4- over 1,2-addition. 

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