Studies in the Pyridazine Series. The Absorption Spectrum of Pyridazine<sup>1</sup>

Evans, Richard Castleman; Wiselogle, F. Y.

doi:10.1021/ja01217a021

Cited by 42 publications

(14 citation statements)

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Section: Resultsmentioning

confidence: 99%

“…We found that the addition of Grignard or organolithium reagents to the readily available 4,5-dihydropyridazin-3(2 H )-one gave rise to a straightforward formation of various tetrahydropyridazinones 5 , albeit in moderate yields (see Experimental Section). With this type of precursor in hand, the multicomponent reaction (MCR) was investigated by mixing pyridazinone 5a , benzaldehyde 3a , and Meldrum’s acid 4 (1 equiv of each). We found that 20 mol % of DABCO in THF for 4 h at 40 °C gave the corresponding diazabicyclononanedione 7a in 38% NMR yield (Table - screening of bases; see Supporting Information (SI) for further details).…”

Section: Resultsmentioning

confidence: 99%

“…4,5-Dihydropyridazin-3(2 H )-one (1 equiv) was introduced in dried glassware under an Ar atmosphere. Three purge-and-refill procedures were carried out (subjected to vacuum and then refilled with argon); then anhydrous toluene (0.1 M) was added.…”

Section: Methodsmentioning

confidence: 99%

“…The title compound was prepared according to the above general procedure from tert-butyl 6-oxo-4,5-dihydropyridazine-3-carboxylate 21 (650 mg, 3.28 mmol, 1 equiv) and NaBH 3 CN (412.2 mg, 6.6 mmol, 2 equiv) in MeOH (16.4 General Procedure for the Synthesis of Tetrahydropyridazinones 5 via Nucleophilic Addition on Dihydropyridazinone. 4,5-Dihydropyridazin-3(2H)-one 12 (1 equiv) was introduced in dried glassware under an Ar atmosphere. Three purge-and-ref ill procedures were carried out (subjected to vacuum and then refilled with argon); then anhydrous toluene (0.1 M) was added.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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The Catalytic Regio- and Stereoselective Synthesis of 1,6-Diazabicyclo[4.3.0]nonane-2,7-diones

et al. 2021

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A straightforward synthesis of original 1,6-diazabicyclo[4.3.0]nonane-2,7-diones was achieved through a DBU-organocatalyzed multicomponent Knoevenagel-aza-Michael-Cyclocondensation (KMC) reaction which takes advantage of an unprecedented highly regio-and diastereoselective conjugate addition of pyridazinones to alkylidene Meldrum's acid intermediates. The key reactive intermediates of this complex process were analyzed by means of electrospray ionization mass spectrometry coupled to ion mobility spectrometry (ESI-IMS-MS) allowing to valid the proposed mechanism.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: ■ Experimental Sectionmentioning

confidence: 99%

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The Catalytic Regio- and Stereoselective Synthesis of 1,6-Diazabicyclo[4.3.0]nonane-2,7-diones

et al. 2021

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“…These reactions were extensively researched and validated by other authors (Evans and Wiselogle, 1945;Kline and Cox, 1961;Oropeza, 2011). Equations (1) and (2) show the reaction of AKGA with HZ and MMH to form PCA and mPCA respectively.…”

Section: Introductionmentioning

confidence: 84%

Toxicity Studies of AKGA/Hydrazines Degradation By-Products and Their Compatibility with Sewage Treatment Plant Operation

Camilo

RandallAndrew

DavisChuck

et al. 2015

Environmental Engineering Science

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A new method to treat hydrazine and monomethylhydrazine (MMH) using a-ketoglutaric acid (AKGA) was proposed. From the reaction of AKGA with hydrazine or MMH, two stable products are formed, 1,4,5,6-tetrahydro-6-oxo-3-pyridazinecarboxylic acid (PCA) and 1-methyl-1,4,5,6-tetrahydro-6-oxo-3-pyridazinecarboxylic acid (mPCA), respectively. With a focus toward use at an industrial facility, tests were undertaken to determine whether waste streams produced from this reaction can be metered into a municipal wastewater facility for final disposal. PCA and mPCA were analyzed for acute toxicity using crustaceans (Ceriodaphnia dubia) and fish (Pimephales promelas) and their effect on the wastewater treatment efficiency and viability using activated sludge (AS) microbes, and their biodegradability by AS organisms. Acute toxicity on crustaceans and fish was investigated according to the methods for acute toxicity by USEPA Method EPA-821-R-02-012. The effect of mPCA and PCA in the treatment efficiency and viability were estimated from respiration inhibition tests (USEPA, 2012) and heterotrophic plate counts. Last, the biodegradability of PCA and mPCA was assessed using the Closed Bottle Method. The results of this study showed that mPCA is significantly more toxic to C. dubia and P. promelas than PCA at the high concentrations ranges used in this study (0.5-1.5 g/L). On the other hand, PCA and mPCA did not show a significant inhibition of carbonaceous respiration of AS microbes at concentrations ranging from 0.5 to 1.5 g/L, although both exhibited some inhibitory effects on nitrification. Under the conditions of this study, PCA was biodegradable by AS while mPCA was not.

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Physical Properties of Pyridazines

Lenhert

Castle

1973

Chemistry of Heterocyclic Compounds: A Series of Monographs

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Studies in the Pyridazine Series. The Absorption Spectrum of Pyridazine¹

Cited by 42 publications

References 0 publications

The Catalytic Regio- and Stereoselective Synthesis of 1,6-Diazabicyclo[4.3.0]nonane-2,7-diones

The Catalytic Regio- and Stereoselective Synthesis of 1,6-Diazabicyclo[4.3.0]nonane-2,7-diones

Toxicity Studies of AKGA/Hydrazines Degradation By-Products and Their Compatibility with Sewage Treatment Plant Operation

Physical Properties of Pyridazines

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Studies in the Pyridazine Series. The Absorption Spectrum of Pyridazine1

Cited by 42 publications

References 0 publications

The Catalytic Regio- and Stereoselective Synthesis of 1,6-Diazabicyclo[4.3.0]nonane-2,7-diones

The Catalytic Regio- and Stereoselective Synthesis of 1,6-Diazabicyclo[4.3.0]nonane-2,7-diones

Toxicity Studies of AKGA/Hydrazines Degradation By-Products and Their Compatibility with Sewage Treatment Plant Operation

Physical Properties of Pyridazines

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Studies in the Pyridazine Series. The Absorption Spectrum of Pyridazine¹