Reactions with 4-Thiohydantoin. Preparation of 5-Arylidene-4-Thiohydantoin, their Reactions towards Grignard Reagents and the Alkylating Agents

1974 ◽  
Vol 29 (1-2) ◽  
pp. 99-103 ◽  
Author(s):  
A. F. A. Shalaby ◽  
H. A. Daboun ◽  
S. S. M. Boghdadi
Keyword(s):  
Double Bond ◽  
Alkylating Agents ◽  
Aromatic Aldehydes ◽  
Grignard Reagents ◽  
Cyclopropane Derivative ◽  
Ethereal Diazomethane

4-Thiohydantoin and 1-phenyl-4-thiohydantoin reacted with aromatic aldehydes to give the corresponding 5-arylidene-4-thiohydantoin (1 a-h). la was obtained also from 5-benzylidene hydantoin and phosphorous pentasulphide. Grignard reagents added to the lateral double bond of (1 a-c) to give after hydrolysis the colorless products 3. Treatment of (1a, b) with alkylating agents gave the corresponding alkylmercapto derivatives (4 a-h). Also (4a, e) were obtained by the action of ethereal diazomethane on (1a, b). By further methylation of (4 e) with diazomethane, a cyclopropane derivative could be isolated.

Synthesen mit Nitrilen, LVII [1]. Zur Reaktivität von Aminomethylen-malonsäuredinitrilen gegenüber Aldehyden und Orthoestern / Syntheses with Nitriles, LVII [1]. The Reactivity of Aminomethylene-malononitriles with Aldehydes and Orthoesters

1979 ◽  
Vol 34 (11) ◽  
pp. 1580-1586 ◽  
Author(s):  
Martin Mittelbach ◽  
Hans Junek
Keyword(s):  
Double Bond ◽  
Aromatic Aldehydes ◽  
Dimethylformamide Dimethylacetal

Abstract Condensation of aminomethy lene-malononitrile (1a) with aromatic aldehydes and dimethylformamide-dimethylacetal, resp., leads to benzylidene-malononitriles (2a, b) and to dimethylaminomethylene-malononitrile (2e), resp. A mechanism of this cleavage of a C=C double bond is discussed. Several substituted enaminonitriles (1e-i) are prepared and the reactivity against aldehydes is studied. Thus, condensation of 3-Amino-2-cyano-crotononitrile (1e) with aldehydes leads to 2-amino-4-phenyl-1,3-butadiene-1,1-dicarbo-nitriles (3). 4-Oxo-2-phenyl-1,2,3,4-tetrahydro-5-pyrimidine-carbonitriles (4) are yielded by the reaction of 3-amino-2-cyano-crotonic-carboxamide (1h) and 3-amino-2-cyano-cinnamamide (1i), resp., with aldehydes. Condensation of 1h and 1i with ethyl ortho-formate leads to 3,4-dihydro-4-oxo-pyrimidine-carbonitriles (6).

Chromium-Catalyzed, Regioselective Cross-Coupling of C–O Bonds by Using Organic Bromides as Reactants

Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2577-2580 ◽  
Author(s):  
Meiming Luo ◽  
Xiaoming Zeng ◽  
Jinghua Tang
Keyword(s):  
Room Temperature ◽  
Cross Coupling ◽  
Aromatic Aldehydes ◽  
Grignard Reagents ◽  
Metallic Magnesium ◽  
Organic Halides

We report a chromium-catalyzed cross-coupling of C–O bonds with widely accessible organic bromides as reactants for the preparation of ortho-arylated or -alkylated aromatic aldehydes at room temperature. The use of metallic magnesium is essential for the reaction to occur, giving it an advantage over previous reactions involving Grignard reagents that have to be prepared separately from organic halides before the coupling.

Reactions with 5-Substituted-1,3-thiazolidine-2,4-dithiones Heterodiene Syntheses

1975 ◽  
Vol 30 (5-6) ◽  
pp. 441-445 ◽  
Author(s):  
Nazmi Abd El Latif Kassab ◽  
Sanaa Osman Abd Allah ◽  
Hamed Abd El Reheem Ead
Keyword(s):  
Double Bond ◽  
Cycloaddition Reaction ◽  
Ethyl Acrylate ◽  
Grignard Reagents

The arylidene derivatives (1) of 1,3-thiazolidine-2,4-dithione undergo 1,4-cycloaddition reaction with acrylonitrile, ethyl acrylate, ω-nitrostyrene, styryl ethyl ketone and N-aryl-maleimides leading to substituted tetrahydrothiopyrano-7 H[2,3-d]thiazole-2thiones (2), (8) and (4).Grignard reagents effects addition to the double bond of the lateral chain of 1 to yield products proved to have structure 7.

The synthesis of 5,6-cyclopropanocholestanes with oxygen functions in positions 3 and 7

1986 ◽  
Vol 51 (2) ◽  
pp. 429-435 ◽  
Author(s):  
Ladislav Kohout
Keyword(s):  
Double Bond ◽  
Cyclopropane Ring ◽  
Hydroxyl Group ◽  
Cyclopropane Derivative

The Simmons-Smith methylenation of the double bond in 3β-acetoxycholest-5-en-7-ols takes place selectively under formation of an adduct the configuration of which is determined by the configuration of the 7-hydroxyl group: 7β-alcohol IV gave 5β,6β-cyclopropane derivative VI, 7α-alcohol V gave 5α,6α-cyclopropane derivative VIII. On photochemically initiated cyclization of 3β-acetoxy-B-homo-5-en-7a-one (XIII) we obtained the product with an α-cyclopropane ring exclusively, i.e. 3β-acetoxy-5,6α-cyclopropano-5α-cholestan-7-one (XII).

scholarly journals Reactions with 2-Acylbenzimidazole Preparation of 2-Cinnamoylbenzimidazoles, their Reactions towards Grignard Reagents and Thiourea

1976 ◽  
Vol 31 (2) ◽  
pp. 254-256 ◽  
Author(s):  
Mohamed I. Ali ◽  
Abd-Elsamei M. Abd-Elfattah ◽  
Hamdy A. Hammouda
Keyword(s):  
Double Bond ◽  
Carbonyl Group ◽  
Grignard Reagents ◽  
Olefinic Double Bond

2-Acetylbenzimidazole condensed with aldehydes to afford the 2-cinnamoyl derivatives (1 a-e). Whereas 2-acetyl- and 2-benzoylbenzimidazole added Grignard reagents at the carbonyl group, the 2-cinnamoyl derivatives (1a, b) suffered addition at the olefinic double bond to give 2a, b. Condensation of amines with 2-acetyl and 2-benzoylbenzimidazole yielded the imino compounds (4a-c). 1 a reacted with thiourea to furnish the pyrimidine (5).

scholarly journals Copper-Catalyzed Asymmetric 1,2-Addition of Grignard Reagents to 3-Acyl 2H-chromenes

Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2624-2628 ◽  
Author(s):  
Adriaan Minnaard ◽  
Beatriz Calvo
Keyword(s):  
Double Bond ◽  
Grignard Reagents ◽  
Tertiary Alcohols ◽  
Carbon Double Bond ◽  
High Yields

Enones in which the carbon–carbon double bond is part of the pharmacologically important 2H-chromene (2H-1-benzopyran) nucleus undergo asymmetric copper-catalyzed 1,2-addition of Grignard reagents. High yields and enantiomeric excesses up to 84% are obtained and access to these novel enantio-enriched tertiary alcohols is provided.

Addition of grignard reagents to the double bond of allylic alcohols

1966 ◽  
Vol 7 (8) ◽  
pp. 875-879 ◽  
Author(s):  
Marc Chérest ◽  
Hugh Felkin ◽  
Claude Frajerman ◽  
Claude Lion ◽  
Georges Roussi ◽  
...  
Keyword(s):  
Double Bond ◽  
Grignard Reagents ◽  
Allylic Alcohols
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