Photochemische reaktionen von äthern mit 4-methylcinnolin und chinoxalinen

1. 4-Methylcinnoline on irradiation in ethers produces the photoproducts 2–6 by a 1.4 addition of the ethers. 2. Quinoxaline reacts with ethers to produce the quinoxalines 8, 12 and 13 by what appears superficially to be a substitution process. Reaction of 2,3-dimethylquinoxaline with tetrahydrofuran gives as the main product 16 by 1.2 addition, and 2-(t-butyl)-quinoxaline gives the dihydroquinoxaline derivatives 17a, b . Because of the known easy autoxidation of 1,2-dihydroquinoxaline we believe that the intermediate in the photolytic reaction of quinoxaline, yielding 8, 12 and 13 , is also the 1.2 addition product. 3. The mass-spectrometric behaviour of the cinnoline and quinoxaline derivatives has been discussed.