ChemicalBook CAS DataBase List 2-(4-fluorophenyl)-3-oxo-2,3-dihydropyridazine-4-carboxylic acid

2-(4-fluorophenyl)-3-oxo-2,3-dihydropyridazine-4-carboxylic acid synthesis

5synthesis methods

Product Name:2-(4-fluorophenyl)-3-oxo-2,3-dihydropyridazine-4-carboxylic acid
CAS Number:946505-09-5
Molecular formula:C11H7FN2O3
Molecular Weight:234.18

Acetaldehyde, 2-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)-, 1-[2-(4-fluorophenyl)hydrazone], (1E)-

946505-08-4
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2-(4-fluorophenyl)-3-oxo-2,3-dihydropyridazine-4-carboxylic acid

946505-09-5
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Yield:946505-09-5 87%

Reaction Conditions:

Stage #1: (E)-5-{2-[2-(4-fluorophenyl)hydrazineylidene]ethylidene}-2,2-dimethyl-1,3-dioxane-4,6-dionewith methanol;sodium methylate for 15 h;Heating / reflux;
Stage #2: with hydrogenchloride in methanol;water;

Steps:

104.C

Step C: Preparation of 2-(4-fluorophenyl)-3-oxo-2,3-dihydropyridazine-4-carboxylic acid; A mixture of (E)-5-(2-(2-(4-fluorophenyl)hydrazono)ethylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (0.60 g, 2.05 mmol) and NaOMe (0.133 g, 2.46 mmol) in MeOH (10 mL) was heated under reflux for 15 hours. The salt was treated with cold 1 N HCl solution, extrated with CH₂Cl₂, dried over MgSO₄, and concentrated to afford 0.42 g (87%) of the desired product. ¹H NMR (400 MHz, CDCl₃) δ 13.57 (br s, 1H), 8.29 (m, 2H), 7.63 (m, 2H), 7.24 (m, 2H); ¹⁹F NMR (376 MHz, CDCl₃) δ -110.7. LRMS (ESI pos) m/e 235.1 (M+1).

References:

US2007/197537,2007,A1 Location in patent:Page/Page column 91