Oxopyrazoline-spiro-oxirans. A new class of reactive heterocycles

Eǧe, Seyhan N.; Adams, Alan D.; GESS, E. J.; Ragone, Katherine S.; KOBER, B. J.; Lampert, Mark B.; Umrigar, Pesi; Lankin, David C.; Griffin, G. W.

doi:10.1039/p19830000325

Cited by 17 publications

(4 citation statements)

References 4 publications

(6 reference statements)

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“…1 H‐NMR spectrum of 5a in DMSO‐ d 6 showed two singlets for two different methyl groups at δ 1.68 and 1.72. This upfield shift as compared with that of the two methyls of the isopropylidene group in derivative (δ 2.6 and δ 2.7 respectively) 4a is attributed to the shielding effect of the oxirane ring . The nonequivalence of the two‐methyl attached to the oxirane ring is due to the basic structure ( 5a ) and also its tautomer ( 5a′ ) in the polar aprotic DMSO‐ d 6 solvent (Scheme ).…”

Section: Resultsmentioning

confidence: 93%

“…Here a modified method was employed to improve the isolated yield of the desired compounds compared with the previous work . Heating of 3 with different carbonyl compounds under solvent‐free condition gave excellent yield of 4‐alkylidene ( 4a and 4b ) or 4‐arylidene derivatives ( 4c‐h ) (chalcone derivatives) (Scheme ) compared with reported literature . 4‐(2′‐Methoxylbenzylidene)‐1‐phenyl‐3,5‐pyrazolidinedione ( 4e ) was ascertained through spectral analysis as 1 HNMR, 13 CNMR, DEPT‐135, COSY, HSQC, and HMBC.…”

Section: Resultsmentioning

confidence: 98%

“…[20,22] Heating of 3 with different carbonyl compounds under solvent-free condition gave excellent yield of 4-alkylidene (4a and 4b) or 4-arylidene derivatives (4c-h) (chalcone derivatives) (Scheme 2) compared with reported literature. [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] 4-(2 0 -Methoxylbenzylidene)-1-phenyl-3,5-pyrazolidinedione (4e) was ascertained through spectral analysis as 1 HNMR, 13 CNMR, DEPT-135, COSY, HSQC, and HMBC. The 2D NMR analysis was in agreement with the proposed structure.…”

Section: Resultsmentioning

confidence: 99%

“…This upfield shift as compared with that of the two methyls of the isopropylidene group in derivative (δ 2.6 and δ 2.7 respectively) 4a is attributed to the shielding effect of the oxirane ring. [25] The nonequivalence of the two-methyl attached to the oxirane ring is due to the basic structure (5a) and also its tautomer (5a 0 ) in the polar aprotic DMSO-d 6 solvent (Scheme 3). Aromatic protons (5H) and the NH or (OH) protons are indicated by a multiplet at δ values 7.247 (1H; para aromatic proton), 7.419 (2H; meta aromatic protons), 7.607 (1H; NH) and 7.624 (2H; ortho aromatic protons).…”

Section: Resultsmentioning

confidence: 99%

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Green synthetic investigation and spectral characterization of some spiro pyrazolidine‐based heterocycles with potential biological activity

El‐Ossaily

Metwally

Al‐Muailkel

et al. 2020

Journal of Heterocyclic Chem

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A green, rapid, and efficient methodology is developed for the synthesis of 1‐phenyl‐3,5‐pyrazolidinedione (3) by the reaction of malonic acid with phenyl hydrazine in the presence of phosphorous oxychloride under solvent‐free conditions. The later compound 3 was used as a versatile precursor for green synthesis of chalcone derivatives (4a‐h) and spiroheterocyclic compounds (5a‐h) with good to excellent isolated yields. The chemical structures of the synthesized compounds were elucidated on the basis of elemental and spectral analyses.

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Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Green synthetic investigation and spectral characterization of some spiro pyrazolidine‐based heterocycles with potential biological activity

El‐Ossaily

Metwally

Al‐Muailkel

et al. 2020

Journal of Heterocyclic Chem

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Direct and Enantioselective Vinylogous Michael Addition of α‐Alkylidenepyrazolinones to Nitroolefins Catalyzed by Dual Cinchona Alkaloid Thioureas

et al. 2014

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While several protocols exist for the asymmetric functionalization of pyrazolinones at the a-position relying on nucleophilic addition or annulation procedures, use of a-alkylidene electronrich analogues in asymmetric vinylogous coupling to carbon electrophiles is substantially an uncharted domain. We now report, for the first time, that alkylA C H T U N G T R E N N U N G idenepyrazolinones carrying an enolizable carbon at the g-position efficiently participate in direct and asymmetric, catalytic vinylogous Michael-type additions to nitroolefins providing the expected adducts in high yields, with complete gsite selectivity and with extraordinary levels of enantio-, diastereo-, and geometrical selectivities. Both enantiomeric adducts were equally accessed by employing a quasi-enantiomeric quinine-or quinidine-based thiourea catalyst pair.

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ChemInform Abstract: OXOPYRAZOLINE‐SPIROOXIRANES. A NEW CLASS OF REACTIVE HETEROCYCLES

Eǧe¹,

Adams²,

GESS³

et al. 1983

Chemischer Informationsdienst

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Oxopyrazoline-spiro-oxirans. A new class of reactive heterocycles

Cited by 17 publications

References 4 publications

Green synthetic investigation and spectral characterization of some spiro pyrazolidine‐based heterocycles with potential biological activity

Green synthetic investigation and spectral characterization of some spiro pyrazolidine‐based heterocycles with potential biological activity

Direct and Enantioselective Vinylogous Michael Addition of α‐Alkylidenepyrazolinones to Nitroolefins Catalyzed by Dual Cinchona Alkaloid Thioureas

ChemInform Abstract: OXOPYRAZOLINE‐SPIROOXIRANES. A NEW CLASS OF REACTIVE HETEROCYCLES

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