1,2,3,4,6-Penta-azaindenes (8-azapurines). Part VI. Methylation of 8-azapurine
Abstract
A practicable methylation of 8-azapurine is described which gives 7-, 8-, and 9-methyl-8-azapurine in approximately equal amounts. After solvent extraction (from aqueous acid), which took advantage of the lower basic strength of the 9-isomer, t.l.c. was used to complete the separation of the isomers. Some alternative procedures are discussed.