Molecules

127 KiB

Open AccessArticle

Amino Acid Based Synthesis of Chiral Long Chain Diamines and Tetramines

by Vassilios Loukas, Theodoros Markidis and George Kokotos

Molecules 2002, 7(10), 767-776; https://doi.org/10.3390/71000767 - 31 Oct 2002

Cited by 2 | Viewed by 8471

A method for the synthesis of long chain diamines and tetramines starting from natural α-amino acids is reported. Diamines and tetramines were prepared through the Wittig olefination reaction of N-protected amino aldehydes obtained from phenylalanine and lysine. A 1,2,17,18-tetramine was synthesized using (2S)-1-azido-2-[bis( [...] Read more.

A method for the synthesis of long chain diamines and tetramines starting from natural α-amino acids is reported. Diamines and tetramines were prepared through the Wittig olefination reaction of N-protected amino aldehydes obtained from phenylalanine and lysine. A 1,2,17,18-tetramine was synthesized using (2S)-1-azido-2-[bis(tert-butoxycarbonyl)-amino]-5-oxopentane as key-intermediate compound. Full article

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52 KiB

Open AccessArticle

A Simple Synthesis of Some New Thienopyridine and Thienopyrimidine Derivatives

by Ahmed M. M. El-Saghier

Molecules 2002, 7(10), 756-766; https://doi.org/10.3390/71000756 - 31 Oct 2002

Cited by 29 | Viewed by 9623

Abstract

A number of pyridothienopyridine (2, 3), pyridothienopyrimidine (6, 10), pyridothienotriazine (13), pyrimidothienopyrimidine (15, 16, 17a,b) and thienoimidazo-triazines (18) were obtained via interaction of 3-amino-5-phenylamino-2,4-dicarbonitrile (1) with different reagents. Full article

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29 KiB

Open AccessArticle

Deprotection of Acetals and Ketals by Silica Sulfuric Acid and Wet SiO₂

by BiBi Fathemeh Mirjalili, Mohamad Ali Zolfigol and Abdolhamid Bamoniri

Molecules 2002, 7(10), 751-755; https://doi.org/10.3390/71000751 - 31 Oct 2002

Cited by 62 | Viewed by 12291

Abstract

Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bonds. A combination of silica sulfuric acid and wet SiO₂ was used as an effective deacetalizating [...] Read more.

Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bonds. A combination of silica sulfuric acid and wet SiO₂ was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under thermal conditions. Full article

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83 KiB

Open AccessArticle

Preparation of Shortened Norbelladine Analogs

by Matthias Treu, Johannes Fröhlich and Ulrich Jordis

Molecules 2002, 7(10), 743-750; https://doi.org/10.3390/71000743 - 31 Oct 2002

Cited by 1 | Viewed by 7296

Abstract

The preparation of N-[(2-bromo-5-hydroxy-4-methoxyphenyl)methyl]-N-[(4-hydroxyphenyl)methyl]formamide (5) and 2-bromo-5-hydroxy-α-[(4-hydroxyphenyl)-methyl]-4-methoxypropaneamide (10) is reported. Full article

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43 KiB

Open AccessArticle

Silica Sulfuric Acid/ NaNO₂ as a Novel Heterogeneous System for the Nitration of Phenols under Mild Conditions

by Mohammad Ali Zolfigol, Elahe Madrakian and Ezat Ghaemi

Molecules 2002, 7(10), 734-742; https://doi.org/10.3390/71000734 - 31 Oct 2002

Cited by 96 | Viewed by 13745

Abstract

Nitrophenols can be obtained in moderate to high yields via nitrosationoxidation of phenols with silica sulfuric acid, NaNO₂ and wet SiO₂ at room temperature. In situ generation of HNO₂ and a radical cation mechanism via the nitrous acid catalyzed (NAC) [...] Read more.

Nitrophenols can be obtained in moderate to high yields via nitrosationoxidation of phenols with silica sulfuric acid, NaNO₂ and wet SiO₂ at room temperature. In situ generation of HNO₂ and a radical cation mechanism via the nitrous acid catalyzed (NAC) pathway appear to be applicable to phenol nitration using these reagents. Full article

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61 KiB

Open AccessArticle

Different Reaction Patterns in the Baylis-Hillman Reaction of Aryl Aldehydes with Phenyl Vinyl Ketone, Phenyl Acrylate and Phenyl Thioacrylate

by Min Shi, Chao-Qun Li and Jian-Kang Jiang

Molecules 2002, 7(10), 721-733; https://doi.org/10.3390/71000721 - 31 Oct 2002

Cited by 15 | Viewed by 11304

Abstract

In the Baylis-Hillman reaction of aryl aldehydes with phenyl vinyl ketone we have observed exclusive formation of diadducts 4, and that the yields of diadduct can reach 80% with increasing amounts of phenyl vinyl ketone. On the other hand, for phenyl acrylate and [...] Read more.

In the Baylis-Hillman reaction of aryl aldehydes with phenyl vinyl ketone we have observed exclusive formation of diadducts 4, and that the yields of diadduct can reach 80% with increasing amounts of phenyl vinyl ketone. On the other hand, for phenyl acrylate and phenyl thioacrylate, only the normal Baylis-Hillman adduct was obtained. The effects of substituents were also examined and a plausible reaction mechanism is proposed for the formation of compounds 4. Full article

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Molecules, Volume 7, Issue 10 (October 2002) – 6 articles , Pages 721-776

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