80843-48-7

Upstream product

• 80843-54-5 ethyl 2,3-dihydro-3-oxo-6-(4-pyridinyl)-4-pyridazinecarboxylate 

Downstream Products

• 80843-53-4 4-amino-6-(4-pyridinyl)-3(2H)-pyridazinone 
• 80843-46-5 2,3-dihydro-3-oxo-6-(4-pyridinyl)-4-pyridazinecarboxylic acid hydrazide 
• 78157-26-3 6-(pyridin-4-yl)pyridazin-3(2H)-one 
• 691848-24-5 N-(2,4-dichlorobenzyl)-3-oxo-6-(pyridin-4-yl)-2,3-dihydropyridazine-4-carboxamide 
• 864464-01-7 4-amino-3-[(3-oxo-6-pyridin-4-yl-2,3-dihydro-pyridazine-4-carbonyl)-amino]-benzoic acid methyl ester 

Relevant academic research and scientific papers

4-Substituted-6-(pyridinyl)-3(2h)-pyridazinones and their use as intermediates and cardiotonics

2-R-4-R'-6-PY-3(2H)-pyridazinones (I) or salts thereof, which are useful as intermediates and some as cardiotonics, are prepared by reacting di-(lower-alkyl) hydroxy[2-oxo-2-PY-ethyl]propanedioate (II) with a hydrazine salt of the formula RNHNH2.nHx An (III) to produce lower-alkyl 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxylate (Ia where R' is lower-carbalkoxy) and reacting Ia with hydrazine hydrate or anhydrous hydrazine to produce 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxylic acid hydrazide (Ib where R' is aminocarbamyl), where PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents, R is hydrogen, lower-alkyl or lower-hydroxyalkyl, R' is carbamyl, carboxy, aminocarbamyl or lower-carbalkoxy, n is 1 or 2, x is 1, 2 or 3, and An is an anion of a strong inorganic acid or an organic sulfonic acid. Also shown are: the preparation of II from PY--COCH3 (IV), the conversion of Ia to Ib (Id where R' is carboxy), and the use of 2-R-4-R"-6-PY-3(2H)-pyridazinones (I where R is lower-alkyl or lower-hydroxyalkyl and R" is carbamyl, aminocarbamyl or lower-carbalkoxy) as cardiotonic agents. Other intermediates are shown.

4-Amino-6-(pyridinyl)-3(2H)-pyridazinones and their use as cardiotonics

4-Amino-2-R-6-PY-3(2H)-pyridazinones (I) or salts thereof, which are useful as cardiotonics, where R is hydrogen, lower-alkyl or lower-hydroxyalkyl, and PY is 4- or 3-pyridinyl or 4- or 3-pyridinyl having one or two lower-alkyl substituents are prepared by: (a) reaction of 2-R-6-PY-3(2H)-pyridazinone (II) with hydrazine; (b) conversion from 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxamide (III); or, (c) conversion form 2,3-dihydro-2-R-3-oxo-6-PY-4-pyridazinecarboxylic acid hydrazide (IV). Also shown are: the use of I or salts as cardiotonic agents; and, the preparation of intermediates.