Regio- and stereoselective microwave-assisted synthesis of 5-alkyl-4-alkenyl-4-phenyl-1,3-oxazolidin-2-ones

Chiral symmetrical alk-2-yne-1,4-diols have been stereoselectively transformed into 5-alkyl-4-alkenyl-4-phenyl-1,3-oxazolidin- 2-ones, which are precursors of quaternary α-amino β-hydroxy acids. The key step was the cyclization of the bis(tosylcarbamates) of 2- phenylalk-2-yne-1,4-diols, easily obtained from the starting chiral diols. These cyclizations were accomplished with complete regioselectivity and up to 92:8 dr in the presence of catalytic amounts of Ni(0) or Pd (II) derivatives under microwave heating.

The synthesis of 1,2,3,6,6a,7-hexahydro-7-methyl-5-imino-1H-pyrrolo[1,2-c]imidazolo[5,4-b]indole

N-3-(1-Methylindol-3-yl)propan-N-(2,2,2-trichloroethoxysulfonyl)guanidine was synthesized from 3-formyl-1-methylindole in six steps and subjected to conditions intended to convert the side-chain into a 2-iminotetrahydropyrimidine- containing product, of relevance to a possible synthesis of the aplicyanins. An alternative reaction course was observed, resulting in the formation of a new tetracyclic system.

The synthesis of 1,2,3,6,6a,7-hexahydro-7-methyl-5-imino-1H-pyrrolo[1,2-c]imidazolo[5,4-b]indole

N-3-(1-Methylindol-3-yl)propan-N-(2,2,2-trichloroethoxysulfonyl)guanidine was synthesized from 3-formyl-1-methylindole in six steps and subjected to conditions intended to convert the side-chain into a 2-iminotetrahydropyrimidine- containing product, of relevance to a possible synthesis of the aplicyanins. An alternative reaction course was observed, resulting in the formation of a new tetracyclic system.

Preparação de N-alquil derivados do 1-bromo-2,4-dinitrobenzeno e do 1-cloro-2-nitrobenzeno: Uma alternativa às aulas práticas de substituição nucleofílica aromática

Preparation of the title compounds are described as an alternative nucleophilic aromatic substitution for practices in the graduate laboratory. The low toxicity and disponibility of the reagents make a suitable procedure approach to experiments regarding this aromatic reaction.

Synthesis and biological activity of n-{5-(4-methylphenyl) diazenyl-4-phenyl-1, 3-thiazol-2-yl}benzamide derivatives

In the present study, various amides of 2-amino-5-(4-methylphenyl)-diazenyl-4-phenyl-1, 3-thiazole was synthesized and their biological activities were evaluated. All the synthesized compounds were characterized by the combination of elemental analysis and standard spectroscopic methods. They are screened for anti-bacterial activity against Escherichia coli and Staphylococcus aureus as well as screened for antifungal activity against Aspergillus niger and Apergillus oryzae by cup plate method at 1 µg/ mL concentration in DMF.

Extração/pré-concentração de íons cobre no ponto nuvem explorando a formação de complexos com DMIT [4,5-dimercapto-1,3-ditiol-2-tionato]

The present study proposes a method for cloud point preconcentration of copper ions at pH 2.0 based on complexes formed with [4,5-dimercapto-1,3-dithyol-2-thionate] and subsequent determination by flame atomic absorption spectrometry (FAAS). Under optimal analytical conditions, the method provided limits of detection of 0.84 and 0.45 µg L-1, by preconcentrating 12.0 and 24.0 mL of sample, respectively. The method was applied for copper determination in water samples, synthetic saliva, guarana powder, tea samples and soft drinks and the accuracy was assessed by analyzing the certified reference materials Dogfish Liver (DOLT-4) and Lobster Hepatopancreas (TORT-2).

Analysis of the structural and electronic properties of 1-(5-Hydroxymethyl - 4 -[ 5 - (5-oxo-5-piperidin-1-yl-penta-1,3dienyl)-benzo[1,3]dioxol-2-yl] -tetrahydro-furan-2-yl)-5-methyl-1H-pyrimidine-2,4dione molecule

The structural and electronic properties of 1-(5-Hydroxymethyl - 4 -[ 5 - (5-oxo-5-piperidin- 1 -yl-penta- 1,3 -dienyl)-benzo [1,3] dioxol- 2 -yl]-tetrahydro -furan-2 -yl)-5-methy l-1Hpyrimidine-2,4dione (AHE) molecule have been investigated theoretically by performing density functional theory (DFT), and semi empirical molecular orbital calculations. The geometry of the molecule is optimized at the level of Austin Model 1 (AM1), and the electronic properties and relative energies of the molecules have been calculated by density functional theory in the ground state. The resultant dipole moment of the AHE molecule is about 2.6 and 2.3 Debyes by AM1 and DFT methods respectively, This property of AHE makes it an active molecule with its environment, that is AHE molecule may interacts with its environment strongly in solution.

Spectrophotometric determination of arsenic in soil samples using 2-(5-bromo-2-pyridylazo)-5-di-ethylaminophenol (Br-PADAP)

In this paper, a new, simple and sensitive method for arsenic determination in soil is proposed. This is based on the reduction of silver (I) and iron (III) ions by arsine followed by a complexation reaction of iron (II) with the spectrophotometric reagent Br-PADAP 2-(5-bromo-2-pyridylazo)-5-di-ethylaminophenol. Arsenic determination with a Sandell's sensitivity of 3.1 10-4 cm-2, linear range from 0.1 µg ml-1 to 2.0 µg ml-1 (r560 = 0.9995), molar absorptivity of 2.45 10(5) l mol-1 cm-1 and a concentration detection limit of 1.4 ng ml-1 (3s) were obtained using a 10 ml sample volume. Selectivity was increased with the use of EDTA as a masking agent. The proposed method was applied for arsenic determination in the presence of several ions amounts in digested soil samples. The results revealed that antimony (III), mercury (II), germanium (IV), platinum (IV) interferes at all analyzed proportions. The interferences can be easily removed by the use of EDTA. Precision and accuracy obtained were satisfactory with a R.S.D. < 5 %. Recovery of arsenic in soil samples varied from 95.55 to 102.70 % with a mean of 99.63 %. These results demonstrated that the proposed method is applicable for arsenic analysis in different soil samples.

1.° Codicis Theodosiani libri sexdecim ; et hîc solae interpretationes. — 2.° Theodosii Junioris, Valentiniani III. Marciani, Majoriani et Severi novellae constitutiones. — 3.° Gaii Institutionum epitome : finis desideratur. — 4.° Julii Pauli sententiarum libri quinque, cum interpretationibus. — 5.° Excerpta ex Codicibus Gregoriano, Hermogeniano et Papianeo. — 6.° Excerpta ex libro quinto etymologiarum Isidori. — 7.° Canones secundi et tertii concilii Aurelianensis. — 8.° Fragmentum concilii Chalcedonensis, de Libertorum ordinationibus. — 9.° Fragmenta legum. — 10.° Edictum Imperatorum Marciani et Valentiniani III. de confirmatione concilii Chalcedonensis

Bigotianus

1.° Flores chronicorum fusiores ; sive catalogus summorum Pontificum à Christo ad Joannem XXII. authore Bernardo Guidonis : praemittitur ejusdem Bernardi vita ; à scriptore coaetaneo scripta. — 2.° Catalogus Regum Francorum à Trojana gentis origine ad Ludovicum X. eodem authore. — 3.° Genealogia Regum Francorum : eodem authore. — 4.° Catalogus Comitum Tolosanorum : eodem authore. — 5.° Nomina Discipulorum Christi ; accedit eorumdem missae officium : eodem authore. — 6.° Ejusdem tractatus brevis de temporibus et annis generalium et particularium Conciliorum. — 7.° Nomina duodecim Apostolorum. — 8.° Catalogus Episcoporum Tolosanorum : authore eodem. — 9.° Ejusdem brevis tractatus de ordinatione officii missae, et de casibus qui inter celebrandum accidere possunt. — 10.° Idem de praeceptis decalogi. — 11.° Idem de articulis fidei. — 12.° Idem de septem sacramentis Ecclesiae. — 13.° Idem de dotibus gloriae Beatorum.

Colbertinus

1.° Martyrologium Usuardi. — 2.° Regula S. Benedicti. — 3.° Lectiones evangeliorum per anni circulum. — 4.° Necrologium Prioratus S. Roberti Conillonis, sive Cornillonis, prope Gratianopolim. — 5.° Liber prosarum S. Mariae Virginis.

Colbertinus

1.° Passio sancti Marcelli, Papae. — 2.° De vita conjugali rectè instituenda ; sive quomodò qui uxorio vinculo ligantur, vitam Deo placitam ducere oporteat, libri tres : authore Jona. — 3.° Vita Ursmari, Episcopi : authore Anaone. — 4.° Vita sancti Ermini, Episcopi.

Faurianus