A Novel Synthesis of Pyrimidines. I. Cyclization of N-Cyano-cyanoaceto Derivatives

抄録

The action of anhydrous hydrogen chloride and bromide on sodium cyanoacetylcyanamides (II) and N-cyano-cyanoacetamidines (IV) was shown to undergo cyclization to give exclusively corresponding 2-halogenopyrimidines (VI, XV), whereas the hydrogen iodide treatment of II caused no cyclization and that of IV gave an unexpected 6-amino-4-iodopyrimidine (XVI). The reaction of II with alcoholic hydrogen chloride afforded 2, 6-dialkoxy-4-hydroxypyrimidines (VIII) via N-cyanoacetyl-O-alkylisoureas (VII). The intermediates (VII) were independently cyclized in water with heating to give 2-alkoxy-6-amino-4-hydroxypyrimidines (IX).