Keten. Part X. The reaction of dimethylketen with pyridine N-oxide

Abstract

PREVIOUS studies on the reaction of dimethylketen with heteroaromatic N-oxides have shown that phenanthridine and isoquinoline N-oxides form adducts containing oxazepinedione rings and also undergo deoxygenation. We now report the results of an investigation of the reaction between pyridine N-oxide and dimethylketen.Dimethylketen failed to react with pyridine N-oxide in ethyl acetate, but reaction in benzene solution gave a mixture of products. Pyridine and 4-isopropylpyridine were isolated and characterised as their picrates, and acetone was isolated and identified as its dinitrophenylhydrazone. In addition, a very low yield of a crystalline solid, C,,H,,N04, was isolated having a composition corresponding to the combination of one molecule of pyridine N-oxide and two molecules of dimethylketen with one extra atom of oxygen.

Keten. Part 19. The reactions of 2,4,6-trimethylbenzonitrile N-oxide with ketens

“…Once again the mass spectra of the adduct showed the base peak at nt/e 146+ with a smaller peak at m/e 147+, whilst the spectrum of the acid had the intensities reversed. The second product isolated from the reaction was a compound, Cl7Ht3NO2, which was clearly not a simple adduct and was assigned the structure (8), largely from the 'H n.m.r. spectrum which contained signals attributable to a 2,4,6-trimethylphenyl group, an isopropyl group with non-equivalent methyl groups, and a methylene group with non-equivalent protons.…”