632333-59-6

Upstream product

• 3043-28-5 3-bromopentane-2,4-dione 
• 115073-23-9 4-Methyl-6-phenyl-1H-pyrazolo[3,4-d]pyrimidin-3-ylamine 
• 123-54-6 acetylacetone 
• 115073-23-9 3-amino-4-methyl-6-phenyl-pyrazolo[3,4-d]pyrimidine 
• 2228-12-8 6-methyl-4-phenyl-2-thioxo-1,2-dihydropyrimidine-5-carbonitrile 
• 82114-04-3 4-hydroxy-6-methyl-2-phenylpyrimidine-5-carbonitrile 
• 115073-24-0 4-hydrazino-6-methyl-2-phenylpyrimidine-5-carbonitrile 
• 914074-37-6 4-chloro-6-methyl-2-phenylpyrimidine-5-carbonitrile 
• 618-39-3 benzamidin 
• 35260-93-6 ethyl 2-cyano-3-ethoxybut-2-enoate 
• 98-88-4 benzoyl chloride 

Relevant academic research and scientific papers

Synthesis of some new 6,8-disubstituted 7,8-dihydropyrimido[2,3:4,3] pyrazolo[1,5-a]pyrimidines and 6,7,8-trisubstituted pyrimido[2,3:4,3]pyrazolo[1, 5-a]pyrimidine derivatives

Cyclization of 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine 4 with excess of 85% hydrazine hydrate afforded the 3-amino-4-methyl-6- phenylpyrazolo[3,4-d]pyrimidine 5, which can react with appropriate Mannich base derivatives 13a-c and chalcones 27a,b to yield the corresponding 6,8-disubstituted 7,8-dihydropyrimido[2,3:4,3]pyrazolo[1,5-a]pyrimidines 15a-c and 30a,b, respectively. On the other hand, the 6,7,8-trisubstituted pyrimido[2,3:4,3]pyrazolo[1,5-a]pyrimidine derivatives 8a-g, 20a-e, 36 and 38 were obtained by treatment of compound 5 with appropriate 1,3-diketones 6a-g, 3-dimethylamino-1-(substituted)prop-2-enones 18a-e, 3-aminocrotononitrile 3, and ethoxymethylenemalononitrile 37 under acidic condition, respectively.

3-Amino-1H-pyrazolopyrimidines and 3-Aminoisothiazolopyrimidines as Precursors of Tricyclic Heteroaromatic Systems Containing a Bridgehead Nitrogen Atom.

3-Amino-4-methyl-6-phenyl-1H-pyrazolopyrimidine (3a) and 3-amino-4-methyl-6-phenylisothiazolopyrimidine (9a) have been prepared.The former reacts with bromoacetone or 3-bromopentane-2,4-dione, to give tricyclic systems (1a) or (13) containing an extra pyrazole or pyrimidine ring, respectively; in each case the newly formed ring contains a bridgehead nitrogen atom, derived from N-2 of the starting material.With the same reagents, the latter undergoes an interesting ring-opening reaction, for which possible mechanisms are proposed.In contrast, 3-amino-1,2-benzisothiazole does not undergo ring fission under similar conditions, but gives rise to tricyclic compounds containing a bridgehead nitrogen atom.