ChemInform Abstract: Photochemical Formation of Heteromethylenecyclopropanes. Part 16. 1,4,5-Substituted Tetrazolium Salts Through Methylation of 1,5-Substituted Tetrazoles and (3 + 2) Cycloaddition of Alkyl Azides to Nitrilium Ions.
Abstract
Methylation of the tetrazoles (I) gives mixtures of the isomerically substituted tetrazolium salts (III) + (IV) which are separated, isolated, and characterized by conversion in better crystallizing tetrafluoroborates, hexafluorophosphates, tetraphenylborates, or perchlorates in strongly varying yields.
ChemInform Abstract
Methylation of the tetrazoles (I) gives mixtures of the isomerically substituted tetrazolium salts (III) + (IV) which are separated, isolated, and characterized by conversion in better crystallizing tetrafluoroborates, hexafluorophosphates, tetraphenylborates, or perchlorates in strongly varying yields. Quaternization of (Ia), (Ic) with tBuOH affords the (IV)-analogues (VI) exclusively. The nitrilium salts (VIII) cycloadd methyl azide (VIIa) to give the salts (IX); the azides (VIIb) are less efficient. Both rate and yield of the (3 + 2) cycloaddition decrease with increasing size of the substituents. The nitrilium salt (X) reacts with (VIIa) to yield the imidoyl chloride salt (XI).
