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79 KiB

Open AccessArticle

A Novel Aromatic Iodination Method, with Sodium Periodate Used as the Only Iodinating Reagent

by Piotr Luliński, Maciej Sosnowski and Lech Skulski

Molecules 2005, 10(3), 516-520; https://doi.org/10.3390/10030516 - 13 May 2005

Cited by 8 | Viewed by 9658

Benzene, halobenzenes and some deactivated arenes readily reacted inanhydrous NaIO₄/AcOH/Ac₂O/concd. H₂SO₄ mixtures to afford, after quenching withexcess aqueous Na₂SO₃ solution (a reducing agent), purified iodinated products in 27-88% yields. This novel method of aromatic iodination is simple, fairly effective andenvironmentally safe. Full article

348 KiB

Open AccessArticle

Investigations on the Formation of 4-Aminobicyclo[2.2.2]-octanones

by Werner Seebacher, Dietmar Kröpfl, Ferdinand Belaj, Robert Saf, Antje Hüfner and Robert Weis

Molecules 2005, 10(3), 521-533; https://doi.org/10.3390/10030521 - 13 May 2005

Cited by 3 | Viewed by 8220

Abstract

Benzylidene acetone reacts with thiocyanates derived from secondary amines in a one-pot reaction to give 4-aminobicyclo[2.2.2]octan-2-ones. The reaction mixture was investigated for the presence of possible intermediates using GC-MS. These intermediates – diketones and enamines – were prepared and exposed to the same [...] Read more.

Benzylidene acetone reacts with thiocyanates derived from secondary amines in a one-pot reaction to give 4-aminobicyclo[2.2.2]octan-2-ones. The reaction mixture was investigated for the presence of possible intermediates using GC-MS. These intermediates – diketones and enamines – were prepared and exposed to the same reaction conditions to examine the reaction mechanism. The reaction of ethyl styryl ketone with thiocyanates of secondary amines yielded cyclohexanone derivatives instead of the expected bicyclo- octanones. Their structures were established by means of a single crystal structure analysis. Full article

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230 KiB

Open AccessArticle

Thermal Behaviour, Biological Activity and Conformational Study of a [Methoprene/β-Cyclodextrin] Complex in a Smoke Generating Formulation

by Paola González Audino, Hector Masuh and Eduardo Zerba

Molecules 2005, 10(3), 534-544; https://doi.org/10.3390/10030534 - 13 May 2005

Cited by 3 | Viewed by 10726

Abstract

Methoprene, an insect growth regulator, was complexed with β-cyclodextrin, yielding a stable inclusion complex. TGA, X-ray powder diffraction and conformational analysis have been used to confirm the nature of this inclusion complex. The interaction between methoprene and β-cyclodextrin was investigated by means of [...] Read more.

Methoprene, an insect growth regulator, was complexed with β-cyclodextrin, yielding a stable inclusion complex. TGA, X-ray powder diffraction and conformational analysis have been used to confirm the nature of this inclusion complex. The interaction between methoprene and β-cyclodextrin was investigated by means of Molecular Mechanics. The results account for the formation of a 1:1 inclusion complex stabilised by Van der Waals forces and hydrogen bonds. The [methoprene–β-cyclodextrin] complex included in smoke generating formulations and protected from thermal decomposition by the foaming agent azodicarbonamide was shown to be stable enough to release methoprene in fumes with good yields. The improved stabilty of the methoprene complex showed a correlation with increased biological activity against Musca domestica. Full article

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54 KiB

Open AccessArticle

Functionalization of 6-Nitrobenzo[1,3]dioxole with Carbonyl Compounds via TDAE methodology

by Ouassila Amiri-Attou, Thierry Terme and Patrice Vanelle

Molecules 2005, 10(3), 545-551; https://doi.org/10.3390/10030545 - 13 May 2005

Cited by 41 | Viewed by 7151

Abstract

We report herein the synthesis of substituted 2-(6-nitrobenzo[1,3]dioxol-5-yl)-1- aryl ethanols and 2-(6-nitrobenzo[1,3]dioxol-5-yl)-propionic acid ethyl esters from the reaction of 5-chloromethyl-6-nitrobenzo[1,3]dioxole with various aromatic carbonyl and α- carbonyl ester derivatives using the tetrakis(dimethylamino)ethylene (TDAE) methodology. Full article

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101 KiB

Open AccessArticle

Synthesis of Some Phenylpropanoid Monoglycerides via the Mitsunobu Protocol

by Daniela I. Batovska, Takao Kishimoto, Vassya S. Bankova, Zornitsa G. Kamenarska and Makoto Ubukata

Molecules 2005, 10(3), 552-558; https://doi.org/10.3390/10030552 - 31 Mar 2005

Cited by 22 | Viewed by 9225

Abstract

Natural monoglycerides of cinnamic, ferulic and p-coumaric acids were synthesized in good to high overall yields from isopropylidene glycerol via the Mitsunobu reaction and further deprotection of the corresponding acetonides with Amberlyst 15. The method avoids the need of protection of the phenolic [...] Read more.

Natural monoglycerides of cinnamic, ferulic and p-coumaric acids were synthesized in good to high overall yields from isopropylidene glycerol via the Mitsunobu reaction and further deprotection of the corresponding acetonides with Amberlyst 15. The method avoids the need of protection of the phenolic hydroxyls. During the Mitsunobu esterifications a strong influence of the acid strength on the efficacy and outcome of the reaction was observed. Full article

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317 KiB

Open AccessArticle

Experimental and Theoretical Studies on the Functionalization Reactions of 4-Benzoyl-1,5-Diphenyl-1H-Pyrazole-3-Carboxylic Acid and Acid Chloride with 2,3-Diaminopyridine

by Ismail Yıldırım, Fatma Kandemirli and Elif Demir

Molecules 2005, 10(3), 559-571; https://doi.org/10.3390/10030559 - 31 Mar 2005

Cited by 18 | Viewed by 8257

Abstract

The 1H-pyrazole-3-carboxylic acid 2 was converted in good yield (69%) into the corresponding 1H-pyrazole-3-carboxamide 5 via reaction of the acid chloride 3 with 2,3- diaminopyridine (4). A different product, the 3H-imidazo[4,5-b] pyridine derivative 6, was formed from the reaction of 3 with 4 [...] Read more.

The 1H-pyrazole-3-carboxylic acid 2 was converted in good yield (69%) into the corresponding 1H-pyrazole-3-carboxamide 5 via reaction of the acid chloride 3 with 2,3- diaminopyridine (4). A different product, the 3H-imidazo[4,5-b] pyridine derivative 6, was formed from the reaction of 3 with 4 and base in benzene for 5 hours. The structures of the synthesized compounds were determined spectroscopically. The mechanism of the reaction between 3 and 4 was examined theoretically. Full article

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268 KiB

Open AccessArticle

Epoxidation and Reduction of DHEA, 1,4,6-Androstatrien-3-one and 4,6-Androstadien-3β,17β-diol

by Eunsook Ma and Eunjeong Kim

Molecules 2005, 10(3), 572-582; https://doi.org/10.3390/10030572 - 25 May 2005

Cited by 12 | Viewed by 9895

Abstract

Dehydroepiandrosterone (DHEA) reacted with m-chloroperoxybenzoic acid(m-CPBA) to form 3β-hydroxy-5α,6α-epoxyandrostan-17-one (1), but it did not reactwith 30% H₂O₂. 1,4,6-Androstatrien-3,17-dione (2) was obtained from DHEA and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. Compound 2 was reacted with 30%H₂O₂ and 5% NaOH [...] Read more.

Dehydroepiandrosterone (DHEA) reacted with m-chloroperoxybenzoic acid(m-CPBA) to form 3β-hydroxy-5α,6α-epoxyandrostan-17-one (1), but it did not reactwith 30% H₂O₂. 1,4,6-Androstatrien-3,17-dione (2) was obtained from DHEA and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. Compound 2 was reacted with 30%H₂O₂ and 5% NaOH in methanol to give 1α,2α-epoxy-4,6-androstadien-3,17-dione (3),which was stereoselectively reduced with NaBH₄ to form 1α,2α-epoxy-4,6-androstadien-3β,17β-diol (7) and reacted with Li metal in absolute ethanol-tetrahydrofuran mixture togive 2-ethoxy-1,4,6-androstatrien-3,17-dione (8). Compound 2 was also epoxidized withm-CPBA in dichloromethane to afford 6α,7α-epoxy-1,4-androstadien-3,17-dione (4),which was reacted with NaBH₄ to synthesize 6α,7α-epoxy-4-androsten-3β,17β-diol (9).Compound 4 was reduced with Li metal in absolute ethanol-tetrahydrofuran mixture toform 7β-ethoxy-6α-hydroxy-1,4-androstadien-3,17-dione (10). Compound 2 was reducedwith NaBH₄ in absolute ethanol to form 4,6-androstadien-3β,17β-diol (5), which wasreacted with 30% H₂O₂ to give the original compound, but which reacted with m-CPBAto give 4β,5β-epoxy-6-androsten-3β,17β-diol (6). Full article

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Molecules, Volume 10, Issue 3 (March-May 2005) – 7 articles , Pages 516-582

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