A clean synthesis of oxazino[5,6-<Emphasis Type="Italic">f</Emphasis>]quinolinone and naphtho[1,2-<Emphasis Type="Italic">e</Emphasis>]oxazinone derivatives

A clean, simple, one-pot, and efficient synthesis of 1,2-dihydro-1-aryl[1,3]oxazino[5,6-f]quinolin-3-one and 1,2-dihydro-1-arylnaphtho[1,2-e]-[1,3]oxazine-3-one derivatives was accomplished in good yields via reaction between 6-quinolinol or 2-naphthol, aromatic aldehydes, and methyl carbamate in aqueous medium catalyzed by TEBA (triethylbenzylammonium chloride). Correspondence: Mohammad Hossein Mosslemin, Department of Chemistry, Islamic Azad University, Yazd 8916871967, Iran.     

Selective and efficient oxidation of sulfides to sulfoxides using ammonium cerium (IV) nitrate in the presence of a catalytic amount of KBr or NaBr

A wide range of aliphatic or aromatic sulfides are selectively oxidized to the corresponding sulfoxides using ammonium cerium (IV) nitrate (CAN) and a catalytic amount of KBr or NaBr in the presence of wet SiO₂ in CH₂Cl₂ under heterogeneous conditions in moderate to high yields. Correspondence: Mohammad Ali Zolfigol, Faculty of Chemistry, Bu-Ali Sina University, P.O. Box 6517838683, Hamadan, Iran; Kamal Amani, Department of Chemistry, Faculty of Science, University of Kurdistan, P.O. Box 6617715175, Sanandaj, Iran.     

A facile and convenient approach to the synthesis of 3,5-diaryl-1<Emphasis Type="Italic">H</Emphasis>-pyrazoles

A simple and convenient one-pot synthesis route is described for the synthesis of 3,5-diaryl-1H-pyrazoles in short reaction times from the reaction of α-epoxyketones with semicarbazide hydrochloride under mild conditions. Correspondence: Farzad Nikpour, Department of Chemistry, Faculty of Sciences, University of Kurdistan, P.O. Box 66315-416, Sanandaj, Iran.     

An efficient three-component reaction involving [3 + 1 + 1] furannulation leading to furanonaphthoquinones in water

An efficient and clean green synthesis of highly substituted linear naphtho[2,3-b]-furan-4,9-dione derivatives, starting from 2-hydroxy-1,4-naphthoquinone, alkyl isocyanides and a variety of aldehydes, is described. This new method provides the first example of an efficient regioselective synthetic method for the synthesis of linear naphtho[2,3-b]-furan-4,9-dione ring systems by formation of three bonds. This [3 + 1 + 1] furannulation strategy affords furanonaphthoquinones in moderate to high yields, using water as a cheap, non-toxic, environmentally friendly solvent, in a one-step reaction, without the need of complicated work-up procedures. Correspondence: Mohammad Bagher Teimouri, Petrochemical Department, Iran Polymer and Petrochemical Institute, P.O. Box 14965-115, Tehran, Iran.     

Regio- and stereoselective synthesis of functionalized oxazolidin-2-ones from the reaction of α-epoxyketones with urea

A regio- and stereoselective synthesis of functionalized 4,5-disubstituted oxazolidin-2-ones is reported with moderate to good yields from the reaction of α-epoxyketones with urea in the presence of p-toluenesulfonic acid as the catalyst. Correspondence: Farzad Nikpour, Department of Chemistry, Faculty of Sciences, University of Kurdistan, P.O. Box 66315-416, Sanandaj, Iran.     

Ammonium chloride catalyzed one-pot synthesis of imidazo[1,2-a]pyridines

Ammonium chloride as a very inexpensive and readily available reagent efficiently catalyzes one-pot, three-component Groebke condensation reactions of aldehydes, isocyanides, and 2-aminopyridines or 2-aminopyrimidines in methanol to afford the corresponding imidazo[1,2-a]pyridines in high yields at room temperature. Correspondence: Ahmad Shaabani, Department of Chemistry, Shahid Beheshti University, PO Box 19396-4716, Tehran, Iran.     

Hetero-<Emphasis Type="Italic">Diels-Alder</Emphasis> reaction of propenenitriles with enol ethers: a convenient approach to functionalized 3,4-dihydro-2<Emphasis Type="Italic">H</Emphasis>-pyrans

The hetero-Diels-Alder reaction of 3-(N-acetyl-N-benzylamino)-2-formylprop-2-enenitrile with enol ethers yielded cis/trans diastereoisomers of 2-alkoxy-4-amino-3,4-dihydro-2H-pyran-5-carbonitriles in moderate yields. Acidic hydrolysis of cis-diastereoisomer in concentrated sulfuric acid gave 2-oxo-1,2-dihydropyrydine-3-carbaldehyde. The reaction of 2-benzoyl-3-heteroaromaticprop-2-enenitriles with enol ethers afforded diastereoisomeric cis/trans cycloadducts in good yields. The structure of the products is discussed in terms of configuration and preferred conformation. Correspondence: Aleksandra Pałasz, Department of Organic Chemistry, Jagiellonian University, Kraków, Poland.     

Synthesis of polyfunctionalized alkenes and α,β-unsaturated γ-lactams from the reaction of alkyl propiolates and CH-acids such as diethyl acetamidomalonate and ethyl acetamidocyanoacetate in the presence of triphenylphosphine

Dialkyl 1-(Z)-2-(acetylamino)-2-butenedioates, 1,1-diethyl-3-alkyl (E)-(1-acetylamino)-2-propene-1,1,3-tricarboxylate, 5-ethyl-1-methyl (E)-4-(acetylamino)-4-cyano-2-pentenedioate and ethyl 1-acetyl-2-cyano-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylate were obtained from the three-component reactions between alkyl propiolates and CH-acids such as diethyl acetamidomalonate and ethyl acetamidocyanoacetate in the presence of triphenylphosphine at room temperature in dry dichloromethane. Correspondence: Sakineh Asghari, Chemistry Department, Mazandaran University, P. O. Box 453, Babolsar, Iran.     

Eco-friendly synthesis of 1,4-benzodiazepine-2,5-diones in the ionic liquid [<Emphasis Type="Italic">bmim</Emphasis>]Br

The green reaction of isatoic anhydrides with α-amino acids in presence of the ionic liquid 1-butyl-3-methylimidazolium bromide afforded 1,4-benzodiazepine-2,5-diones in excellent yields in absence of a catalyst. The reaction workup is simple and the ionic liquid was easily recovered from the reaction and reused. The methodology was quite general and a range of cyclic and acyclic α-amino acids were examined to produce 1,4-benzodiazepine-2,5-diones. Correspondence: Khosrow Jadidi, Department of Chemistry, Shahid Beheshti University, PO Box 1983963113, Tehran, Iran.     

Synthesis of pyrazolo[4,3-<Emphasis Type="Italic">e</Emphasis>][1,2,4]triazolo[4,3-<Emphasis Type="Italic">c</Emphasis>]pyrimidines

Starting from 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones, a synthesis pathway to the tricyclic pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines is described. Reaction of 1,5-dihydro-4H-pyrazolo[3,4-d] pyrimidin-4-ones with phosphoryl chloride afforded the corresponding 4-chloro-1H-pyrazolo[3,4-d]pyrimidines. Treatment of these compounds with hydrazine hydrate at reflux temperature gave the hydrazino derivatives, which were subsequently cyclized to the titled compounds on heating with orthoesters in ethanol. Correspondence: Abolghasem Davoodnia, Department of Chemistry, School of Sciences, Islamic Azad University, Mashhad Branch, Mashhad 91735-413, Iran.     

Synthesis of α-amino-β-keto-esters (β-oxodipeptides)

The synthesis of α-amino-β-keto-esters (β-oxo dipeptides) was studied. Corresponding α-amino-β-ketoesters were prepared from BOC-(L)-Valine and BOC-(L)-isoleucine by coupling with (D,L)-threonine hydrochloride and oxidation with Dess-Martin periodinane (DMP) with a total yield of 48% and 38%, respectively. __________ Translated from Chemistry Online, 2007, 70(10): 793–796 [译自: 化学通报]     

Conformational study of a strained tolanophane by dynamic 1H NMR spectroscopy and computational methods

The existence of a short C–H ⋯ π (alkyl–alkyne) interaction in the structure of a strained and relatively rigid tolanophane is expected to hinder the rotation about the C–C sp³ single bond. Variable-temperature NMR experiments (performed in three solvents, CDCl₃, THF-d₈, and acetone-d₆) and ab initio density functional calculations were carried out to investigate its dynamic nature. An energy barrier of 48.6 kJ/mol is determined at coalescence (210 K) with acetone-d₆ which is in good agreement with calculation result (54 kJ/mol). Correspondence: Hossein Reza Darabi, Chemistry and Chemical Engineering Research Center of Iran, Pajoohesh Blvd., km 17, Karaj Hwy, 14968-13151 Tehran, Iran.     

Efficient synthesis of 2-thioxo-1,3-thiazolanes from primary amines, CS2, and ethyl bromopyruvate

An efficient synthesis of 2-thioxo-1,3-thiazolanes is described via reaction of carbon disulfide, ethyl bromopyruvate, and primary amines. Correspondence: Issa Yavari, Chemistry Department, Tarbiat Modares University, PO Box 14115-175, Tehran, Iran.     

An efficient synthesis of 2-cyano-2-phenyl-2,11b-dihydro-[1,3]oxazino[2,3-a]isoquinolines by reaction of isoquinoline with electron-deficient acetylenes in the presence of benzoylcyanide

Isoquinoline reacts with electron-deficient acetylenic compounds in the presence of benzoylcyanide to form 2-cyano-2-phenyl-2,11b-dihydro-[1,3]oxazino[2,3-a]isoquinolines in good yields. Correspondence: Issa Yavari, Chemistry Department, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.     

Bader's interatomic surfaces are unique

 In this work we comment on the statement about the nonuniqueness of the solution of Bader's equation for defining atoms in molecules reported in the article of P. Cassam-Chena? and D. Jayatilaka in Theoretical Chemistry Accounts (2001) 105: 213–218 Received: 10 May 2001 / Accepted: 7 September 2001 / Published online: 3 June 2002     

One-pot synthesis of functionalized thioureas by reaction of benzoyl isothiocyanates, secondary amines, and alkyl propiolates

An efficient one-pot synthesis of functionalized thioureas is described via three-component reaction of benzoyl isothiocyanates, secondary amines, and alkyl propiolates in the presence of triphenylphosphine (20 mol%). Correspondence: Issa Yavari, Chemistry Department, Tarbiat Modares University, PO Box 14115-175, Tehran, Iran     

Efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates from the reaction of carbon disulfide and primary amines in the presence of diethyl 2-chloromalonate

An efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates via reaction of primary amines with CS₂ in the presence of diethyl 2-chloromalonate is described. Correspondence: Issa Yavari, Chemistry Department, Tarbiat Modares University, PO Box 14115-175, Tehran, Iran.     

Synthesis of a functionalized tetrahydro-1,4-thiazepine in water as the solvent and theoretical investigation of its tautomeric structures

Reaction of sodium 2,2-dicyanoethene-1,1-bis(thiolate) with 2-chloroethylamine hydrochloride in water afforded the novel (Z)-5-amino-7-thioxo-2,3,4,7-tetrahydro-1,4-thiazepine-6-carbonitrile. The molecular geometry of the most stable tautomeric structure was investigated with DFT and AIM at the B3LYP level of theory using the standard 6-31G** basis set. Correspondence: Mehdi Bakavoli, Department of Chemistry, School of Science, Ferdowsi University, 91775-1436 Mashhad, Iran.     

Synthesis of fully substituted iminolactones via a three-component condensation of isocyanides and acetylenic esters with 2-bromo-1-(4-bromophenyl)ethanone

A novel three-component condensation reaction between an isocyanide, an electron-deficient acetylenic ester, and 2-bromo-1-(4-bromophenyl)‐ethanone efficiently provides fully substituted iminolactones in a one-pot condensation reaction without any activation or modification in high yields. Correspondence: Ahmad Shaabani, Department of Chemistry, Shahid Beheshti University, P.O. Box 19396-4716, Tehran, Iran.