The 1,4-naphthoquinones are an important group of compounds intensively studied because of their wide range of biological activities. Four 2-chloro-3-(substituted-phenylamino)-1,4 naphthoquinone derivatives were synthesized, and the vibrational modes of these molecules were assigned using Raman and Fourier transform infrared spectroscopy (FTIR) techniques. In addition, X-ray studies were performed for one of these derivatives. Density functional theory (DFT) calculations were also developed for these compounds and presented. In summary, the results obtained from these studies can assess chemical changes in the structures of functionalized quinones and the discovery of candidate biologically active compounds.

In this work, we report the synthesis of three series of carbohydrate-based benzo[f]indole-4,9-diones and amino-1,4-naphthoquinone derivatives and evaluated their cytotoxic activity against eight human cancer cell lines. Several compounds showed a promising cytotoxic activity toward the tumor cell lines (half maximal inhibitory concentration (IC50) < 10.0 μM). The importance of the substitution pattern of the quinone derivatives on the antitumor activity was also discussed. 3-Carboethoxy-2-methyl-benzo[f]indole-4,9-dione derivatives were more cytotoxic than their parent compounds and amino-1,4-naphthoquinones. Unlike clinically useful anticancer agent doxorubicin, the majority of synthesized compounds did not exhibit any lytic effects against erythrocytes or normal human leukocytes.

Neste trabalho nós descrevemos o uso do ultrassom na síntese de novas naftoquinonas, 6a-f e 7a-c, contendo na posição 2 do anel quinonoídico substituintes do tipo aminocarboidratos. Estas substâncias foram preparadas, em condições brandas, através da reação da 1,4-naftoquinona (8a) ou do metoxi-lapachol (8b) com diferentes aminocarboidratos 9a-d. As estruturas das substâncias foram confirmadas através das técnicas de RMN de ¹H e de 13C-APT, uni- e bi-dimensionais (COSY-¹H vs. ¹H e HETCOR ¹J CH), e por espectrometria de massas de alta resolução com ionização por electrospray (ESI MS).

In this report we describe the ultrasound-accelerated synthesis of new naphthoquinone derivatives 6a-f and 7a-c, which possess an aminocarbohydrate chain at the C-2 position of the quinone ring. This novel type of 1,4-naphthoquinone derivative has been synthesized under mild conditions by the reaction of 1,4-naphthoquinone (8a) or methoxylapachol (8b) with different aminocarbohydrates 9a-d. Characterization of all substances was confirmed by one- and two-dimensional nuclear magnetic resonance (NMR) techniques (¹H, 13C-APT, cosy-¹H vs. ¹H and HETCOR ¹J CH) and by high-resolution electrospray ionization mass spectrometry (HR ESI MS).

The 1,2,3-triazole, known since the end of 19th century, is a very widely used heterocyclic system present in many synthetic substances and commercial pharmaceutical compounds. In fact, 1,2,3-triazoles show several applications in many areas especially as medicines against many diseases like cancer, AIDS, Parkinson and Alzheimer. Nowadays there is a large variety of known methods to obtain these heterocyclic compounds comprising mainly three synthetic routes. Nevertheless, there is no article that gives an objective overview of the synthetic methods for obtaining these kinds of azoheterocycles. This paper presents a brief history of this class of compounds, and a synthetic discussion concerning the main synthetic methods for its preparation, such as cyclization through hydrazones, concerted cycloadditon [2+3] and pseudopericyclic cyclization - and some others of restricted application, but also important. Finally, this paper also provides a brief overview on pharmacological applications of some 1,2,3-triazoles.

Neste trabalho estão descritas as sínteses dos ribonucleosídeos pirrólicos reversos 5-C-(4-acetil-5-metil-pirrol-1-il)-2,3-O-isopropilideno-5-desoxi- beta-D-ribofuranosídeo de metila (10), 5-C-(4-etoxicarbonil-5-metil-pirrol-1-il)-2,3-O-isopropilideno-5-desoxi- beta-D-ribofuranosídeo de metila (11), 5-C-(4-acetil-5-metil-pirrol-1-il)-5-desoxi-beta-D-ribofuranosídeo de metila (12), 5-C-(4-etoxicarbonil-5-metil-pirrol-1-il)-5-desoxi- beta-D-ribofuranosídeo de metila (13), 5-desoxi-5-C-(3'-formil-4'-hidroxipropil-pirrol-1'-il)-2,3-O-isopropilideno- beta-D-ribofuranosídeo de metila (16) e 5-desoxi-5-C-(3'-formil-pirrol-1'-il)-2,3-O-isopropilideno- beta-D-ribofuranosídeo de metila (18) a partir do 5-amino-5-desoxi-2,3-O-isopropilideno-beta-D-ribofuranosídeo de metila (9), matéria-prima de fácil preparação. A estratégia sintética para a construção do anel heterocíclico baseou-se no ataque nucleofílico da amina 9 aos diidrofuranos: 4-acetil-2-n-butoxi-5-metil-4,5-diidrofurano (4), 4-carbetoxi-2-n-butoxi-5-metil-4,5-diidrofurano (5), 4-formil-2-n-butoxi-4,5-diidrofurano (6) e 4-formil-1-metil dioxabiciclo[3.3.0]oct-3-eno (8, in situ), obtidos através da reação dos diazo compostos 3-diazo-2,4-pentadiona (1), 2-diazoacetoacetato de etila (2) e diazomalonaldeído (3) com enol-éteres, sob catálise de tetraacetato de di-ródio.

The synthesis of reverse pyrrole ribonucleosides methyl 5-C-(4-acetyl-5-methyl-pyrrol-1-yl)-2,3-O-isopropylidene-5-deoxy- beta-D-ribofuranoside (10), methyl 5-C-(4-ethoxycarbonyl-5-methyl-pyrrol-1-yl)-2,3-O-isopropylidene-5-deoxy- beta-D-ribofuranoside (11), methyl 5-C-(4-acetyl-5-methyl-pyrrol-1-yl)-5-deoxy-beta-D-ribofuranoside (12), methyl 5-C-(4-ethoxycarbonyl-5-methyl-pyrrol-1-yl)-5-deoxy- beta-D-ribofuranoside (13), methyl 5-deoxy-5-C-(3'-formyl-4'-hydroxypropyl-pyrrol-1'-yl)-2,3-O-isopropylidene- beta-D-ribofuranoside (16) and methyl 5-deoxy-5-C-(3'-formyl-pyrrol-1'-yl)-2,3-O-isopropylidene- beta-D-ribofuranoside (18) are described starting from readily available methyl 5-amino-5-deoxy-2,3-O-isopropylidene-beta-D-ribofuranoside (9). The synthetic strategy for the construction of the heterocyclic ring was based on the nucleophilic attack of (9) to 4-acetyl-2-n-butoxy-5-methyl-4,5-dihydrofuran (4), 4-carbetoxy-2-n-butoxy-5-methyl-4,5-dihydrofuran (5), 4-formyl-2-n-butoxy-4,5-dihydrofuran (6) and 4-formyl-1-methyl dioxabyciclo[3.3.0]oct-3-en (8, in situ). The later compounds were obtained from reaction between 3-diazo-2,4-pentadione (1), ethyl 2-diazoacetoacetate (2) or diazomalonaldehyde (3) and enol ethers using dirhodium tetraacetate as a catalyst.

Diazocarbonyl compounds are a very important class of organic substances which have a long history of useful aplications in organic chemistry. The focus of this report deals with the use of diazocarbonyl compounds in a ariety of important reactions and their application in organic synthesis. These reactions are briefly summarized showing their broad scope.