The Hantzsch pyrrole synthesis

1970 ◽  
Vol 48 (11) ◽  
pp. 1689-1697 ◽  
Author(s):  
M. W. Roomi ◽  
S. F. MacDonald
Keyword(s):  
Carboxylic Acids ◽  
Ethyl Acetoacetate ◽  
Alkyl Group ◽  
Ethyl Esters ◽  
Hantzsch Synthesis ◽  
Butyl Esters ◽  
Alkyl Groups

Ethyl esters of 2-alkyl- and 2,4-dialkylpyrrole-3-carboxylic acids are obtained generally by extensions of the Hantzsch synthesis, benzyl and t-butyl esters when the 2-alkyl group is methyl. Hemopyrrole is obtained from butanal and ethyl acetoacetate in three steps. Pyrroles bearing higher alkyl groups or carbobenzoxy groups are reductively alkylated like the corresponding methylpyrroles and carbethoxy derivatives; t-butyl esters do not survive.

scholarly journals Cytotoxicity against HL60 Cells of Ficifolidione Derivatives with Methyl, n-Pentyl, and n-Heptyl Groups

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4081
Author(s):  
Hisashi Nishiwaki ◽  
Megumi Ikari ◽  
Satomi Fujiwara ◽  
Kosuke Nishi ◽  
Takuya Sugahara ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
Alkyl Group ◽  
Caspase 3 ◽  
Biological Activities ◽  
Mosquito Larvae ◽  
Leukaemia Cell ◽  
Leukaemia Cell Line ◽  
Hl60 Cells ◽  
Flow Cytometric ◽  
Alkyl Groups

Ficifolidione, a natural insecticidal compound isolated from the essential oils of Myetaceae species, is a spiro phloroglucinol with an isobutyl group at the C-4 position. We found that ficifolidione showed cytotoxicity against cancer cells via apoptosis. Replacement of the isobutyl group by n-propyl group did not influence the potency, but the effect of the replacement of this group by a shorter or longer alkyl group on the biological activity remains unknown. In this study, ficifolidione derivatives with alkyl groups such as methyl, n-pentyl, and n-heptyl group—instead of the isobutyl group at the C-4 position—were synthesized to evaluate their cytotoxicity against the human promyelocytic leukaemia cell line HL60 and their insecticidal activity against mosquito larvae. The biological activities of their corresponding 4-epimers were also evaluated. As a result, the conversion of the isobutyl group to another alkyl group did not significantly influence the cytotoxicity or insecticidal activity. In HL60 cells treated with the n-heptyl-ficifolidione derivative, the activation of caspase 3/7 and the early stages of apoptosis were detected by using immunofluorescence and flow cytometric techniques, respectively, suggesting that the cytotoxicity should be induced by apoptosis even though the alkyl group was changed.

The Alkyl Inductive Effect, II Theoretical Calculation of Inductive Parameters

1979 ◽  
Vol 34 (2) ◽  
pp. 321-326 ◽  
Author(s):  
Harry F. Widingand ◽  
Leonard S. Levitt
Keyword(s):  
Electric Field ◽  
Alkyl Group ◽  
Bond Model ◽  
Chemical Effects ◽  
Alkyl Groups ◽  
Alkyl Substitution ◽  
Internal Induction ◽  
Experimental Values ◽  
Physical And Chemical ◽  
Calculated Distance

AbstractThree models of alkyl groups, “derealization”, “through-the-bond”, and “electric field” models, are presented, all of which enable the calculation of σI (R) from first principles, and excellent agreement is demonstrated for the calculated and experimental values of σI (R) . For the “delocalization” model it is found that - σI (R) = 0.0455 + 0.0232(1-1/n), where n is the number of C atoms in an n-alkyl group, and for an infinite C-chain R group, σI( R∞) is - 0.0687, identical to the value found b y a different method in Part I of this series. The “through-the-bond” model gives - σI(R) = - 0.0559 +, where Ci is the number of C-atoms in the i th position from X in RX; and for the “electric field” model, we obtain - σI(R) = 0.0463 + 0.0102 , where di is the calculated distance from C1 to Cn in the most probable conformation of the R-group. It is concluded that Taft's σI(R) values have a real significance whether or not the physical and chemical effects of alkyl substitution reside ultimately in an internal induction mechanism, or in alkyl group polarization by charged centers in the molecule, or a combination of the two.

Photochemistry of ethyl esters of α-oxo-carboxylic acids

1990 ◽  
Vol 53 (1) ◽  
pp. 77-85 ◽  
Author(s):  
A.L. Zanocco ◽  
E.A. Soto ◽  
E.A. Lissi ◽  
J.C. Scaiano
Keyword(s):  
Carboxylic Acids ◽  
Ethyl Esters
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