43 research outputs found
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
The Synthesis of 2Substituted 3Dimethylaminopropenoates and Related Compounds and Their Application to the Synthesis of Heterocyclic Systems
Synthesis of Heterocycles from Alkyl 3-(Dimethylamino)propenoates and Related Enaminones
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