Transformations of 4-Amino-5-cyanopyrimidines. The Synthesis and Transformations of Pyrimido-/4,5-d/Pyrimidines

Several new approaches to the synthesis of pyrimido/4,5- -d/pyrirnidines are described. 5-Cyano-4-(N,N dimethylaminomethyleneamino)- 2-methylthiopyrimidine (2) and 5-cyano-4-ethoxyethyleneamino- 2-methylthiopyirimidine (12) cyclize with hydrazine into 3-amino-4-imino-2-methylthio-3,4-dihydropyrimido/4,5-d/pyrimidine (3) which can be deaminated into 4-amino-2-methylthiopyrimido/ 4,5-d/pyrimidine (4). On the other hand, 5-cyano-4-hydroxyiminomethyleneamino- 2-methylthio- (14) and -2-methoxopyrimidine (15) cyclize thermally into 4-amino-7-methylthio- (16) and 4-amino-7-methoxypyrimido/4,5-d/pyrimidine 3-oxide (17), respectively

Synthesis of 2-substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidin-4(3H)-ones

2-Substituted 6-(5-oxo-1-phenylpyrrolidin-3-yl)pyrimidin-4(3H)-ones were synthesized in three steps from itaconic acid derivatives via cyclization with primary amines followed by Masamune-Claisen condensation, and cyclization of the newly formed β-keto esters with amidines. Preparation and/or isolation of β-keto esters with polar N-substituents failed, but the corresponding final products were obtained in a different way. 6-(1-(3-Hydroxypropyl)-5-oxopyrrolidin-3-yl)-2-phenylpyrimidin-4(3H)-one was obtained by hydrogenolytic o-deprotection of its o-benzyl derivative. Depending on reaction conditions, further mesylation of 6-(1-(3-(benzyloxy)propyl)-5-oxopyrrolidin-3-yl)-2-phenylpyrimidin-4(3H)-one followed by treatment with pyrrolidine gave either the monoaminated- or the diaminated product. The structures of novel compounds were determined by NMR

Reactions of Quinolizine-and Pyridino[1,2-a]pyrimidine-3-diazonium Tetrafluoroborates with Aliphatic Amines*

Reactions of 1-cyano-4-oxo-4H-quinolizine-3-diazonium tetrafluoroborate (1a) and 4-oxo-4H-pyridino[1,2-a]pyrimidine-3-diazonium tetrafluoroborate (1b) with aliphatic amines 2a -g were studied. Treatment of heteroaryldiazonium salts 1 with secondary amines 2a -d afforded the corresponding N-alkyl-N'-heteroaryltriazenes 3a -h in high yields. On the other hand, reactions of 1a with aliphatic primary amines 2e -g resulted in an unexpected rearrangements into the corresponding picolinic acid N-alkylcarboxamides 4a -c