Molecules

48 KiB

Open AccessArticle

Synthesis and Reactions of Furo[2,3-b]pyrroles

by A. Krutosiková, C. A. Ramsden, M. Dandárová and A. Lycka

Molecules 1997, 2(4), 69-79; https://doi.org/10.3390/20400069 - 20 Apr 1997

Cited by 16 | Viewed by 10864

Methyl 6H-furo[2,3-b]pyrrole-5-carboxylate (2a) was prepared by thermolysis of the corresponding methyl 2-azido-3-(3-furyl)propenoate (1). 6-Methyl (2b) and 6-benzyl (2c) derivatives were obtained using phase-transfer catalysis conditions (PTC). The formylation of 2a-2c gave 2-formylated compounds (3a-3c). Compounds 4b, 4c were prepared by reactions [...] Read more.

Methyl 6H-furo[2,3-b]pyrrole-5-carboxylate (2a) was prepared by thermolysis of the corresponding methyl 2-azido-3-(3-furyl)propenoate (1). 6-Methyl (2b) and 6-benzyl (2c) derivatives were obtained using phase-transfer catalysis conditions (PTC). The formylation of 2a-2c gave 2-formylated compounds (3a-3c). Compounds 4b, 4c were prepared by reactions of corresponding esters 2b, 2c with hydrazine in refluxing ethanol. By reaction of 3a-3c with hydroxylammonium chloride in acetic anhydride in the presence of pyridine, methyl 2-cyano-6-R¹-furo[2,3-b]pyrrole-5-carboxylates (5a-5c) were obtained. The reaction of these compounds with sodium azide and ammonium chloride in dimethylformamide led to methyl 2-(5'-tetrazolyl)-6-R¹-furo[2,3-b]pyrrole-5-carboxylates (6a-6c). A series of 5-methoxycarbonyl-6-R¹-furo[2,3-b]pyrrole-2-carbaldehyde N,N-dimethylhydrazones (7a-7c) was prepared from methyl 2-formyl-6-R¹-furo[2,3-b]pyrrole-5-carboxylates (3a-3c) and unsym-dimethylhydrazine. The correlation of the ¹³C and ¹⁵N chemical shifts with the data of the calculated (AM1) net atomic charges is discussed. Full article

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81 KiB

Open AccessShort Note

1-Ethyl 4-(2-oxopropyl) 2-(1,2,3,4-Tetrahydro-1,3-dimethyl-2,4-dioxopyrimidin-5-yl)butanedioate

by Jin-Cong Zhuo and Hugo Wyler

Molecules 1997, 2(4), M9; https://doi.org/10.3390/M9 - 15 Apr 1997

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Abstract

n/a Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

81 KiB

Open AccessShort Note

1-Ethyl 4-(1,1-dimethylethyl) 2-(1,2,3,4-Tetrahydro-1,3-dimethyl-2,4-dioxopyrimidin-5-yl)butanedioate

by Jin-Cong Zhuo and Hugo Wyler

Molecules 1997, 2(4), M8; https://doi.org/10.3390/M8 - 15 Apr 1997

Cited by 1 | Viewed by 3384

Abstract

The diester 2 was prepared by the addition of tert-butanol to 1 according to the reported procedure [1].[...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

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Scheme 1

81 KiB

Open AccessShort Note

1-Ethyl 4-(1-methylethyl) 2-(1,2,3,4-Tetrahydro-1,3-dimethyl-2,4-dioxopyrimidin-5-yl)butanedioate

by Jin-Cong Zhuo and Hugo Wyler

Molecules 1997, 2(4), M7; https://doi.org/10.3390/M7 - 15 Apr 1997

Viewed by 3456

Abstract

The diester 2 was prepared by the addition of iso-propanol to 1 according to the reported procedure [1].[...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

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81 KiB

Open AccessShort Note

1-Ethyl 4-propyl 2-(1,2,3,4-Tetrahydro-1,3-dimethyl-2,4-dioxopyrimidin-5-yl)butanedioate

by Jin-Cong Zhuo and Hugo Wyler

Molecules 1997, 2(4), M6; https://doi.org/10.3390/M6 - 15 Apr 1997

Cited by 12 | Viewed by 3493

Abstract

The diester 2 was prepared by the addition of propanol to 1 according to the reported procedure [1] [...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

81 KiB

Open AccessShort Note

1-Ethyl 4-(2-methoxyethyl) 2-(1,2,3,4-Tetrahydro-1,3-dimethyl-2,4-dioxopyrimidin-5-yl)butanedioate

by Jin-Cong Zhuo and Hugo Wyler

Molecules 1997, 2(4), M5; https://doi.org/10.3390/M5 - 15 Apr 1997

Cited by 22 | Viewed by 3424

Abstract

The diester 2 was prepared by the addition of 2-methoxyethanol to 1 according to the reported procedure [1].[...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

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Scheme 1

82 KiB

Open AccessShort Note

N-(3,4-Dichlorophenyl)methyl Oxamic Acid

by Shu-Kun Lin

Molecules 1997, 2(4), M4; https://doi.org/10.3390/M4 - 15 Apr 1997

Cited by 12 | Viewed by 3636

Abstract

A mixture of N-(3,4-dichlorophenyl)methyl oxamic acid ethyl ester [1] (7.609 g, 27.56 mmol), ethanol (400 ml), NaOH (1N, 32 ml) and water (200ml) was stirred at r.t. overnight under N₂.[...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

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Scheme 1

83 KiB

Open AccessShort Note

N,N'-bis[(3,4-Dichlorophenyl)methyl]ethanediamide

by

Molecules 1997, 2(4), M3; https://doi.org/10.3390/M3 - 15 Apr 1997

Viewed by 3531

Abstract

n/a Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

81 KiB

Open AccessShort Note

Propyl 3-(1,2,3,4-Tetrahydro-1,3,6-trimethyl-2,4-dioxopyrimidin-5-yl)butanoate

by Jin-Cong Zhuo and Hugo Wyler

Molecules 1997, 2(4), M10; https://doi.org/10.3390/M10 - 15 Apr 1997

Viewed by 3397

Abstract

The compound 2 was prepared by the addition of propanol to 1 according to the reported procedure [1].[...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

80 KiB

Open AccessShort Note

1,3-Di(4-benzyloxybenzoyl)indole

by Shu-Kun Lin

Molecules 1997, 2(4), M1; https://doi.org/10.3390/M1 - 15 Apr 1997

Cited by 1 | Viewed by 4411

Abstract

The general part of the experimental section [1] has been presented elsewhere.[...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

38 KiB

Open AccessArticle

o-Nitroaryl-bis(5-methylfur-2-yl)methanes as Versatile Synthons for the Synthesis of Nitrogen-Containing Heterocycles

by Alexander V. Butin, Vladimir T. Abaev, Tat’yana A. Stroganova and Andrey V. Gutnov

Molecules 1997, 2(4), 62-68; https://doi.org/10.3390/20400062 - 10 Apr 1997

Cited by 30 | Viewed by 8852

Abstract

2-Nitroaryldifurylmethanes 1a and 1b, readily available by condensation of 2-nitrobenzaldehyde and 6-nitroveratraldehyde with 2-methylfuran, were transformed into indole, cinnoline and benzothiazine-3,1 derivatives. The reduction of 2-nitroaryldifurylmethanes gave the corresponding anilines 2a,b or indole 3 depending on the reaction conditions. A plausible mechanism for [...] Read more.

2-Nitroaryldifurylmethanes 1a and 1b, readily available by condensation of 2-nitrobenzaldehyde and 6-nitroveratraldehyde with 2-methylfuran, were transformed into indole, cinnoline and benzothiazine-3,1 derivatives. The reduction of 2-nitroaryldifurylmethanes gave the corresponding anilines 2a,b or indole 3 depending on the reaction conditions. A plausible mechanism for the last reaction involving intramolecular heterocyclic addition between a nitroso-group and a furan ring is proposed. Diazotisation of the amine 2b gave a cinnoline derivative - a product of intramolecular oxidative furan ring opening. Treatment of isothiocyanates 7a,b with perchloric acid resulted in a new rearrangement with furan ring migration leading to the 4-Hbenzothiazine-3,1 derivatives. Full article

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Molecules, Volume 2, Issue 4 (April 1997) – 11 articles , Pages 62-79, Articles M1-M9

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