HETEROCYCLES

■ Contents

■ Tetrazolecarbaldehydes and Their Derivatives

Dietrich Moderhack*

*Institute of Medicinal and Pharmaceutical Chemistry, Technical University, Braunschweig, Beethovenstrasse 55, D-38106, Germany

Abstract

This article summarizes the preparative chemistry of the three classes of tetrazolecarbaldehydes (A–C) including derivatives. Certain comparisons between A–C and their closest analogues, the 1,2,4-triazolecarbaldehydes (D–F), are drawn.

■ One-Pot Synthesis of Benz[f]Indolo[3,2-c]isochromeno- 5,7,13-trione Derivatives from 2-Amino-1,4-naphtho-quinones and Ninhydrin

Ting Zhou, Guang-Yu Pan, Dao-Lin Wang,* and Jian-Hua Qian

*Liaoning Key Laboratory of Synthesis and Application of Functional Compound, College of Chemistry & Chemical Engineering, Bohai University, Jinzhou 121001, China

Abstract

An efficient method for the preparation of novel benz[f]indolo[3,2-c]-isochromeno-5,7,13-triones 3 was described. The construction of this new pentacyclic system was achieved undergo a domino reaction of 2-amino-1,4-naphthoquinones 1 with ninhydrin 2 in one-pot with good yields.

■ The Reactivity of 4’-Substituted Spiro[Isoindole-1,3’-pyrazoles] Derivatives: Substitution/Elimination Reactions and Access to Biaryl Derivatives

Benedetta Maggio, Gianfranco Fontana, Maria Valeria Raimondi, Demetrio Raffa, Fabiana Plescia, Angela Maria Ingarra, and Giuseppe Daidone*

*STEBICEF, University of Palermo, Via Archirafi 32, 90123 Palermo, Italy

Abstract

This paper describes aspects of the chemistry of 4’-substituted spiro[isoindole-1,3’-pyrazoles]. These compounds underwent substitution and/or elimination reactions to afford some new spiro– as well as biaryl derivatives of potential pharmaceutical relevance. Mechanistic considerations are discussed as well.

■ Expeditious Synthesis of Carboxylic Esters and High-Yielding Macrolactones Using Trifluoromethyl-Substituted Benzoic Anhydrides with 4-(Dimethylamino)pyridine: an Evaluation of The Reactivities of Aromatic Acid Anhydrides as Dehydration Reagents Compared with 2-Methyl-6-nitrobenzoic Anhydride

Isamu Shiina* and Takayuki Tonoi

*Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan

Abstract

Trifluoromethyl-substituted benzoic anhydrides as structural congeners of 2-methyl-6-nitrobenzoic anhydride (MNBA) were prepared and investigated for comparative reactivity in the synthesis of carboxylic esters and macrolactones. 2-Fluoro-6-(trifluoromethyl)benzoic anhydride (FTFBA) was found to be a promising dehydrating agent in the presence of 4-(dimethylamino)pyridine (DMAP), and was successfully employed in the synthesis of threo-aleuritic acid lactone in good yield with high chemoselectivity.

■ One-Pot and Efficient Synthesis of 5-Aminopyrazole-4-carbonitriles Catalyzed by Potassium Phthalimide

Hamzeh Kiyani* and Maryam Bamdad

*School of Chemistry, Damghan University, Cheshmeh Ali Road, Daneshgah square, Damghan 36715-364, Iran

Abstract

The potassium phthalimide (PPI) has been found to be an efficient, recyclable, inexpensive, commercially available, and easy to handle catalyst for the synthesis of 5-aminopyrazole-4-carbonitriles through the one-pot, three-component reaction of easily available starting reactants involving aldehydes, phenylhydrazine, and malononitrile. This reaction was performed in a mixture of EtOH:H2O as a green reaction media at 50 °C. The catalyst could be recovered easily from the filtrate via evaporation of solvent and reused many times. The present eco-friendly three-component cyclocondensation offers main benefits including, time-saving, mild conditions, minimize the amount of waste, high atom efficiency, avoiding the hazardous organic solvents or catalysts, and the ease of the work-up.

■ Synthesis of (-)-Isosolenopsin Using Diastereoselective Aminopalladation

Yukiko Takemoto, Yasunao Hattori, and Hidefumi Makabe*

*Sciences of Functional Foods, Graduate School of Agriculture, Shinshu University, 8304 Minamiminowa-mura, Kamiina-gun, Nagano 399-4598, Japan

Abstract

Concise synthesis of (-)-isosolenopsin, a piperidine alkaloid isolated from the fire ants (Solenopsis) was achieved. 2,6-Disubstituted piperidine ring of (-)-isosolenopsin was constructed using diastereoselective aminopalladation. Chain elongation using Grubbs 2nd catalyst followed by reduction of double bond and deprotection of the Boc group afforded (-)-isosolenopsin.

■ A One-Pot, Green Synthesis of Betti Base Containing Adenine Derivatives in Aqueous Medium

Dulin Kong, Zhongxiang Zhu, Jie Jiang, Luyong Wu, Xianghui Wang, Zaifeng Shi, Qiang Lin,* and Mingshu Wu*

*Chemical Engineering College, Nanjing University of Science & Technology, Nanjing, Jiangsu 210094, P. R. China
Key Laboratory of Tropical Medicinal Plant Chemistry of the Ministry of Education, College of Chemistry & Chemical Engineering, Hainan Normal University, Haikou 571158, P.R. China

Abstract

A one-pot, three-component condensation reaction of 2-naphthol, adenine and aliphatic or aromatic aldehydes in aqueous medium to give Betti base containing adenine derivatives in the presence of p-toluenesulfonic acid for the first time, is described. The present approach offers several advantages such as good yields, mild conditions (80 oC), clear reaction profile and simple work-up procedure. The entitled compounds are characterized by IR, NMR and HRMS.

■ A New Chromone Derivative from an Endophytic Fungus Xylaria sp. Isolated from Ardisia crenata

Ken-ichi Nakashima,* Junko Tomida, Masanori Tabata, Takao Hirai, Yuji Morita, Yoshiaki Kawamura, and Makoto Inoue

*Laboratory of Medicinal Resources, Faculty of Pharmaceutical Sciences, Aichi Gakuin University, 1-100 Kusumoto-cho Chikusa-ku Nagoya city 464-8650, Japan

Abstract

A new chromone derivative, xylariacetal (1), and a known isocoumarin, mullein (2), were isolated from Xylaria sp. ECN-008, which was derived from the leaves of Ardisia crenata. The structure of the new compound was identified by various spectroscopic techniques including 1D- and 2D-NMR. Xylariacetal (1) exhibits a characteristic tricyclic structure with an acetal moiety.

■ A Multi-Component One-Pot Synthesis of Novel (1,3,4-Thiadiazin-2-ylamino)isoindoline-1,3-diones as Antimicrobial Agents

Rizk E. Khidre,* Bakr F. Abdel-Wahab, and Ghada E. A. Awad

*Chemistry Department, National Research Center Jazan University, KSA Cairo, Egypt

Abstract

A series of new (1,3,4-thiadiazin-2-ylamino)isoindoline-1,3-dione derivatives 5, 8, 9, 11a-d, and 13a,b were prepared via one-pot three component reaction of isobenzofuran-1,3-dione 1, thiocarbohydrazide 2 and various α-halocarbonyl compounds. The chemical structure of the new compounds was elucidated by spectral analyses and X-ray single crystal technique. The newly synthesized compounds were also evaluated for their in vitro antimicrobial activity, and showed promising results.

■ New Two Pebrolide Derivatives, 14-Deacetoxy-1-deoxypebrolide and 7’-Hydroxyasperphenamate Isolated from Penicillium sp. IFM62525

Syuhei Arai, Daigo Wakana, Takeshi Itabashi, Hisashi Takeda, Takashi Yaguchi, Galba Maria de Campos Takagi, and Tomoo Hosoe*

*Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan

Abstract

New two pebrolide type sesquiterpenoids, deacetoxy-1-deoxypebrolide (1) and 7’-hydroxyisoasperphenamate (2) along with asperphenamate (3), mycophenolic acid (4) and 1-deoxypebloride (5) were isolated from Penicillium sp. IFM 62525. Their structures were established from spectroscopic and chemical method. The absolute stereochemistry of 2 was confirmed by Marfey’s method. Antifungal activities of these compounds were tested and 4 showed strong activity.

■ A Facile Synthesis of Novel Pyrido[2’,1’:2,3]Imidazo[4,5-c] β-Carbolines

Liang Yan, Dao-Lin Wang,* and Jian-Hua Qian

*Liaoning Key Laboratory of Synthesis and Application of Functional Compound, College of Chemistry & Chemical Engineering, Bohai University, Jinzhou 121001, China

Abstract

An efficient tandem process for the synthesis of pyridoimidazo-fused β-carbolines: pyrido[2”,1”:2’,3’]imidazo[4’,5’:2,3]pyrido[4,5-b]indole, is described. The construction of these compounds was achieved by one-pot three component reaction of 1-benzyl-1H-indole-3-carbaldehyde, 2-aminopyridine and trimethylsilyl cyanide via Groebke-Blackburn-Bienaymé reaction, followed by cyclization through the Pictet-Spengler reaction of the resulting imidazo[1,2-a]- pyridine which allowed access to the title heterocycles.

■ Facile and Short-Step Synthesis of 5-Substituted 2,3,4,5-Tetrahydrobenz[f][1,4]Oxazepines Using a Modified Pictet-spengler Reaction

Toshiaki Saitoh, Michikazu Kitabatake, Takuya Sugimoto, Hiromu Kawakubo, Kunihiko Mohri, and Yoshie Horiguchi*

*Faculty of Pharmaceutical Sciences, Showa Pharmaceutical University, 3-3165, Higashi-tamagawagakuen, Machida, Tokyo 194-8543, Japan

Abstract

5-Substituted 2,3,4,5-tetrahydrobenzo[f][1,4]oxazepines (6) were synthesized using a modified Pictet-Spengler reaction of formyliminium ion (4) as the key step. Cyclization of 4 proceeded readily by using trifluoroacetic acid as a catalyst, giving 5-substituted N-formyl- 2,3,4,5-tetrahydrobenzo[f][1,4]oxazepines (5) in 26–78% yield. The imination of 2-phenoxyethanamine (1) with aldehydes, formylation of the resulting imines (3), and the acid-catalyzed cyclization steps could be carried out in a one-pot procedure. Hydrolysis of 5 with hydrochloric acid gave the 5-substituted 2,3,4,5-tetrahydrobenzo[f][1,4]oxazepines (6) in high yields.

■ Errata “Synthesis of β-Glycosyl Formamides Through N-Glycosylation of Unprotected Carbohydrates”:Heterocycles, 2016, 92, 2201, Doi: 10.3987/Com-16-13584

Yoshiyasu Ichikawa,* Akihito Matsukawa, Mitsutoshi Maeda, Hasuka Tomishige, Yumiko Tomita, Rika Mimura, Ayumi Kitamori, Hiyoshizo Kotsuki, Keiji Nakano, and Toshiya Masuda

*Faculty of Science, Kochi University, 2-5-1, Akebono-cho, Kochi 780-8520, Japan