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Synthesis of nitrogen‐containing heterocycles 9 . Preparation and carbon‐carbon bond cleavage of spiro[cycloalkane[1′,2′,4′]‐triazolo[1′,5′‐ a ][1′,3′,5′]triazine] derivatives and related compounds
Author(s) -
Miyamoto Yoshiko
Publication year - 2000
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570370629
Subject(s) - chemistry , cycloalkane , moiety , triazine , reagent , medicinal chemistry , organic chemistry , carbon fibers , alkyl , ring (chemistry) , catalysis , materials science , composite number , composite material
Abstract Diaminomethylenehydrazones of cyclic ketones 1–5 reacted with ethyl N ‐cyanoimidate (I) at room temperature or with bis(methylthio)methylenecyanamide (II) under brief heating to give directly the corresponding spiro[cycloalkane[1′,2′,4′]triazolo[1′,5′,‐ a ][1′,3′‐5′]triazine] derivatives 7–12 in moderate to high yields. Ring‐opening reaction of the spiro[cycloalkanetriazolotriazine] derivatives occurred at the cycloalkane moiety upon heating in solution to give 2‐alkyl‐5‐amino[1,2,4]triazolotriazines 13–16. Diaminomethylenehydrazones 17–19, of hindered acyclic ketones, gave 2‐methyl‐7‐methylthio[1,2,4]‐triazolo[1,5‐ a ][1,3,5]triazines 21–23 by the reaction with II as the main products with apparent loss of 2‐methylpropane from the potential precursor, 2‐ tert ‐butyl‐2‐methyl‐7‐methylthio[1,2,4]triazolo[1,5‐ a ]‐[1,3,5]triazines 20, in good yields. In general, bis(methylthio)methylenecyanamide II was found to be a favorable reagent to the one‐step synthesis of the spiro[cycloalkanetriazolotriazine] derivatives from the diaminomethylenehydrazones. The spectral data and structural assignments of the fused triazine products are discussed.