123420-41-7

Upstream product

• 51251-34-4 diethyl 2-((3-hydroxypyridin-2-ylamino)methylene)malonate 
• 16867-03-1 2-amino-3-hydroxypyridine 
• 87-13-8 diethyl 2-ethoxymethylenemalonate 
• 24016-03-3 2-amino-3-benzyloxypyridine 
• 123420-40-6 Diethyl N-(3-benzyloxy-2-pyridyl)aminomethylenemalonate 

Downstream Products

• 50876-74-9 3-ethoxycarbonyl-9-hydroxy-4-oxo-4H-pyrido<1,2-a>pyrimidine 

Relevant academic research and scientific papers

4H-PYRIDO[1,2-a]PYRIMIDIN-4-ONE COMPOUNDS

The present invention relates to compounds of the formula I or II: (I) (II) processes for their preparation and their use as pharmaceutical agents or compositions in the treatment, of neurological disorders.

Synthesis of New Heterocyclic Phenols: 9-Hydroxypyridopyrimidin-4-one and Derivatives

9-Hydroxypyridopyrimidin-4-one (5) was prepared by condensation of 2-amino-3-hydroxypyridine with isopropylidene aminomethylenemalonate.The reaction first led to an enaminoester intermediate which underwent cyclization by heating at 250 deg C affording the new heterocyclic phenol 5.A similar condensation performed on 2-amino-3-benzyloxypyridine yielded the corresponding benzylic ether which can be easily debenzylated to 5 by hydrogenolysis.Furthermore 2-amino-3-benzyloxypyridine condensed with diethyl ethoxymethylenemalonate gave 9-benzyloxy-3-ethoxycarbonylpyridopyrimidin-4-one which was also debenzylated to the corresponding free phenol.

SYNTHESIS OF NEW HETEROCYCLIC PHENOLS : 9-HYDROXY-PYRIDO PYRIMIDINE-4-ONE AND 9-HYDROXY-PYRIMIDOPYRIMIDINE-4-ONE

The novel title phenols have been prepared by condensation of a derivative of Meldrum acid with 3-benzyloxy-2-amino-pyridine or 5-benzyloxy-4-amino-pyrimidine, and subsequent hydrogenolysis of the protecting group.