Phosphorylation of 2‐(3‐methyl‐1,3‐diazabuten‐1‐yl)‐3‐ethoxycarbonylthiophenes with phosphorus(III) halides

2‐(3‐Methyl‐1,3‐diazabuten‐1‐yl)‐3‐ethoxycarbonylthiophenes are phosphorylated with phosphorus(III) halides in basic media at position 5 of the thiophene ring. Up to three heteroaromatic substituents can be introduced one by one at the same phosphorus atom. On this basis, mono‐, bis‐, and trishetaryl substituted P(III) and P(V) derivatives have been obtained. Phosphorylated 2‐(N,N‐dimethylformamidino)‐3‐ethoxycarbonylthiophenes provide a synthetic access to phosphorylated thienopyrimidines. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:641–651, 2001     

Reactions of 2,3‐dihydro‐1H‐1,5‐benzodiazepines and chloroacetyl chlorides: Synthesis of 2a,3,4,5‐tetrahydro‐azeto [1,2‐a][1,5] benzodiazepin‐1(2H)‐ones

2a,4‐Disubstituted 5‐benzoyl‐2‐chloro/2,2‐dichloro‐2a,3,4,5‐tetrahydro‐azeto [1,2‐a] [1,5]benzodiazepin‐1 (2H)‐ones ( 3a–h ) were synthesized by cycloaddition reactions of 2,4‐disubstituted 1‐benzoyl‐2,3‐dihydr o‐1H‐1,5‐benzodiazepines ( 2a–h ) and ketenes, generated from chloroacetyl chloride or dichloroacetyl chloride in the presence of triethylamine, in anhydrous benzene. In some cases, ring contraction of benzodiazepines has also been observed. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:636–640, 2001     

Enantioselective reduction of 2‐keto‐3‐haloalkane phosphonates by baker's yeast

Bioreduction of 3‐substituted‐2‐oxoal‐kanephosphonates by baker's yeast afforded 3‐substituted‐2‐hydroxy‐alkanephosphonates in moderate to good yields and ee value. These compounds could serve as useful chirons for the stereoselective synthesis of phosphorus analogs of biologically active molecules including R‐(—)‐3‐trimethylammonium‐2‐hydroxypropanoic acid and R‐(—)‐3‐ trimethylammonium‐2‐hydroxypropanoic acid. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:551–556, 2001     

Synthesis of spiro[3,4‐diaryl‐4,5‐dihydroisoxazole‐5,2′‐1′,2′,3′,4‐tetrahydro‐1′‐naphthalenone]

Synthesis of a series of novel spiro[3,4‐diaryl‐4,5‐dihydroisoxazole‐5,2′‐1′,2′,3′,4′‐tetrahydro‐1′‐naphthalenone] has been described by the regioselective cycloaddition of nitrile oxides with 2‐arylmethylene‐1,2,3,4‐tetrahydro‐1‐naphthalenone. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:463–467, 2001     

Anionic polymerization of 4‐phenyl‐1‐buten‐3‐yne derivatives bearing electron‐withdrawing groups

The anionic polymerization of derivatives of 4‐phenyl‐1‐buten‐3‐yne was carried out to investigate the effect of substituents on the polymerization behavior. The polymerization of 4‐(4‐fluorophenyl)‐1‐buten‐3‐yne and 4‐(2‐fluorophenyl)‐1‐buten‐3‐yne in tetrahydrofuran at −78 °C with n‐BuLi/sparteine as an initiator gave polymers consisting of 1,2‐ and 1,4‐polymerized units in quantitative yields with ratios of 80/20 and 88/12, respectively. The molecular weights of the polymers were controlled by the ratio of the monomers to n‐BuLi, and the distribution was relatively narrow (weight‐average molecular weight/number‐average molecular weight < 1.2), supporting the living nature of the polymerization. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1016–1023, 2001     

Synthesis and antimicrobial activity of 8‐alkylcarbamato‐16H‐dinaphtho [2,1‐d:1′,2′‐g] 1,3,2‐dioxaphosphocin 8‐oxides

A new family of phosphorus heterocycles, namely 8‐alkylcarbamato‐16H‐dinaphtho‐[2,1‐d: 1′,2′‐g] 1,3,2‐dioxaphosphocin 8‐oxides ( 4a–j ) has been obtained by reaction of bis(2‐hydroxy‐1‐naphthyl)methane ( 3 ) with a series of dichlorophosphosphinyl carbamates ( 2a–j ) in dry toluene in the presence of triethylamine at 40–45°C. The intermediates 2a–j were obtained by the addition of alcohols/thiol to isocyanatophosphonic dichloride ( 1 ) at −10°C in dry toluene. The structures of the title compounds were confirmed by the elemental analyses, IR, ¹H, ¹³C, and ³¹P NMR spectra. The FAB mass spectrum of one member of the family is discussed. These compounds were found to possess good antimicrobial activity. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:16–20, 2001     

Soluble fluorinated polyimides derived from 1,4‐ (4′‐aminophenoxy)‐2‐(3′‐trifluoromethylphenyl)benzene and aromatic dianhydrides

New fluorinated aromatic polyimides were prepared from 1,4‐(4′‐aminophenoxy)‐2‐(3′‐trifluoromethylphenyl)benzene and aromatic dianhydrides via the polycondensation of one‐step high‐temperature and two‐step thermal or chemical imidization methods. Experimental results indicated that some of the polyimides were soluble both in strong dipolar solvents (N‐methyl‐2‐pyrrolidone or N,N‐dimethylacetamide) and in common organic solvents such as tetrahydrofuran, CHCl₃, and acetone. The polyimides showed exceptional thermal and thermooxidative stability and good mechanical properties. No weight loss was detected before a temperature of 520 °C in nitrogen, and the glass‐transition temperatures ranged from 208 to 251 °C. Low dielectric constants (2.55–2.71 at 1 MHz), low refractive indices, and low water absorption were also observed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2404–2413, 2001     

Reaction of 2‐amino‐3‐cyano‐4,5,6,7‐tetrahydrobenzo‐[b]thiophene with ethyl acetoacetate: Novel syntheses of pyridines,pyrazoles, and their fused derivatives

The reaction of 2‐amino‐3‐cyano‐4,5,6,7‐tetrahydrobenzo[b]thiophene 1 with ethyl acetoacetate 2 gave compound 3 . The reactivity of the latter product toward a variety of chemical reagents was studied to give fused thiophene derivatives of potential pharmaceutical interest. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:518–527, 2001     

Thermolysis of 3‐alkyl‐3‐methyl‐1,2‐dioxetanes: Activation parameters and chemiexcitation yields

3‐Methyl‐3‐(3‐pentyl)‐1,2‐dioxetane 1 and 3‐methyl‐3‐(2,2‐dimethyl‐1‐propyl)‐1,2‐dioxetane 2 were synthesized in low yield by the α‐bromohydroperoxide method. The activation parameters were determined by the chemiluminescence method (for 1 ΔH‡ = 25.0 ± 0.3 kcal/mol, ΔS‡ = −1.0 entropy unit (e.u.), ΔG‡ = 25.3 kcal/mol, k₁ (60°C) = 4.6 × 10⁻⁴s⁻¹; for 2 ΔH‡ = 24.2 ± 0.2 kcal/mol, ΔS‡ = −2.0 e.u., ΔG‡ = 24.9 kcal/mol, k₁ (60°C) = 9.2 × 10⁻⁴s⁻¹. Thermolysis of 1–2 produced excited carbonyl fragments (direct production of high yields of triplets relative to excited singlets) (chemiexcitation yields for 1: ϕ^T = 0.02, ϕ ≤ 0.0005; for 2: ϕ^T = 0.02, ϕ^S ≤ 0.0004). The results are discussed in relation to a diradical‐like mechanism. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:459–462, 2001     

Synthesis and antimicrobial activity of 2,10‐dichloro‐6‐substituted‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides/sulfides

Novel 2,10‐dichloro‐6‐substituted‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐oxides ( 4a–h ) were synthesized by reacting 5,5′‐dichloro‐3,3′‐dinitro‐2,2′‐dihydroxydiphenylmethane ( 2 ) with different aryl phosphorodichloridates ( 3a–g ) or bis(2‐chloroethyl)phosphoramidic dichloride ( 3h ) in the presence of triethylamine at 55–60°C, and the compounds 4i–l were prepared by reacting the 2,6,10‐trichloro‐4,8‐dinitro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐sulfide ( 5 ) in situ with substituted phenols and thiophenol 5 was prepared by condensing 2 with thiophosphoryl chloride. IR, ¹H, ¹³C, ³¹P NMR, and mass spectra supported all the proposed structures. Several title compounds exhibited significant activity in the assays against the bacteria Bacillus subtilis and Escherichia coli and fungi Curvularia lunata and Aspergillus niger. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:10–15, 2001     

Gas‐phase pyrolysis of 2‐heteroaromatic‐1‐dimethylaminoethylenes: Kinetic and mechanistic study

Gas‐phase pyrolysis reactions of 4(2′‐dimethylaminoethenyl)‐2‐oxo‐2H‐benzo[b]pyran‐3‐carbonitrile ( 1 ), 4(2′‐dimethylaminoethenyl)‐2‐oxo‐2H‐naphtho[1,2‐b]pyran‐3‐carbonitrile ( 2 ), 1,6‐dihydro‐4‐(2′‐dimethylaminoethenyl)‐6‐oxo‐1‐phenylpyridazine‐3,5‐dicarbonitrile ( 3 ), 2‐cyano‐5‐dimethylamino‐3‐phenyl‐2,4‐pentadienonitrile ( 4 ), 2‐cyano‐5‐dimethylamino‐3‐(2‐thienyl)‐2,4‐pentadienonitrile( 5 ), 1,2‐dihydro‐4‐(2′‐dimethylaminoethenyl)‐oxo‐quinoline‐4‐carbonitrile ( 6 ), 6‐(ethylthio)‐4‐(2′‐dimethylaminoethenyl)‐2‐phenylpyrimidine‐5‐carbonitrile ( 7 ) (Scheme 1) have been carried out. The rates of gas‐phase pyrolytic reactions of compounds 3, 4, 5, and 7 have been measured and found to correspond to unimolecular first‐order reactions. Product analyses together with kinetic data were used to outline a feasible pathway for the pyrolytic reactions of the compounds under study. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:47–51, 2001     

Thermolysis of 3‐alkyl‐3‐methyl‐1,2‐dioxetanes: activation parameters and chemiexcitation yields

3‐Methyl‐3‐(3‐pentyl)‐1,2‐dioxetane 1 and 3‐methyl‐3‐(2,2‐dimethyl‐1‐propyl)‐1,2‐dioxetane 2 were synthesized in low yield by the α‐bromohydroperoxide method. The activation parameters were determined by the chemiluminescence method (for 1 ΔH‡ = 25.0 ± 0.3 kcal/mol, ΔS‡ = −1.0 entropy unit (e.u.), ΔG‡ = 25.3 kcal/mol, k₁ (60°C) = 4.6 × 10⁻⁴s⁻¹; for 2 ΔH‡ = 24.2 ± 0.2 kcal/mol, ΔS‡ = −2.0 e.u., ΔG‡ = 24.9 kcal/mol, k₁ (60°C) = 9.2 × 10⁻⁴s⁻¹. Thermolysis of 1–2 produced excited carbonyl fragments (direct production of high yields of triplets relative to excited singlets) (chemiexcitation yields for 1: ϕ^T = 0.02, ϕ^S ≤ 0.0005; for 2: ϕ^T = 0.02, ϕ^S ≤ 0.0004). The results are discussed in relation to a diradical‐like mechanism. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:176–179, 2001     

Reaction with hydrazonoyl halides. Part 32 [1]: Reaction of C‐acyl‐N‐(3‐phenyl‐5‐pyrazolyl)hydrazonoyl chlorides with potassium thiocyanate and synthesis of some new 2,3‐dihydro‐1,3,4‐thiadiazoles and slenadiazoles

C‐acyl‐N‐(3‐phenyl‐5‐pyrazolyl)hydrazonoyl chlorides 1a,b react with potassium thiocyanate and potassium selenocyanate to give 5‐acyl‐2,3‐dihydro‐2‐imino‐3‐(3′‐phenyl)pyrazol‐5′‐yl)‐1,3,4‐thiadiazoles 2a,b and 5‐acetyl‐2,3‐dihydro;‐2‐imino‐3‐(3′‐phenyl)pyrazol‐5′‐yl)‐1,3,4‐selenadiazole 10a,b . Also, 2‐[mercapto‐(methylthio)methylene]indan‐1,3‐dione 16 reacts with hydrazonoyl halides 15 and 22–25 to afford 2,3‐dihydro‐1,3,4‐thiadiazoles 19 and 26–29 , respectively. Structures of the newly synthesized compounds are elucidated on the basis of spectral data, chemical transformations, and alternative synthesis methods. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:468–474, 2001     

Synthesis of 1,3,3a,5‐tetraaryl‐3a,4,5,6‐tetrahydro‐3H‐1,2,4‐triazolo[4,3‐a] [1,5]benzodiazepines

A series of 3a,5‐diaryl‐1,3‐diphenyl‐3a,4,5,6‐tetrahydro‐3H‐1,2,4‐triazolo[4,3‐a][1,5]benzo‐diazepines was synthesized by the cycloaddition reactions of 2,4‐diaryl‐2,3‐dihydro‐1H‐1,5‐benzo‐diazepines and N‐phenylbenzonitrileimine generated from N‐phenylbenzenecarbohydrazonic chloride in the presence of triethylamine in anhydrous tetrahydrofuran. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:557–559, 2001     

Theoretical study of the internal rotational barriers in nitrobenzene, 2‐nitrotoluene, 2‐nitrophenol,and 2‐nitroaniline

The molecular geometries and internal rotational barriers of the nitro group of nitrobenzene (NB), 2‐nitrotoluene (2‐NT), 2‐nitroaniline (2‐NA), and 2‐nitrophenol (2‐NP) were calculated by five different types of density functional theory (DFT) methods with three different levels of basis sets. Analysis of the torsional angles of the nitro, methyl, amino, and hydroxyl groups indicate that NB, 2‐NA, and 2‐NP are planar molecules, but 2‐NT is not a planar molecule. Internal rotational barriers of the nitro group were calculated as V₂ barriers, and the NO₂ torsional potentials for each molecule were given. The values of the V₂ barriers depend on the DFT methods and basis sets. The average values of the V₂ barriers for NB, 2‐NT, 2‐NA, and 2‐NP are 6.47 kcal/mol, 3.00 kcal/mol, 10.20 kcal/mol, and 13.26 kcal/mol, respectively. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 83: 332–337, 2001     

Synthesis and bioactivities of 1,3,2‐benzodiazaphosphorin‐2‐carboxamide 2‐oxides containing α‐aminophosphonate groups

In order to search for novel antitumor and antiviral agents with high activity and low toxicity, a series of 1‐ethoxycarbonylmethyl‐3‐ethyl‐1,2,3,4‐tetrahydro‐4‐oxo‐1,3,2‐benzodiazaphosphorin‐2‐carboxamide 2‐oxides containing α‐aminophosphonate groups have been designed and synthesized by a convenient one‐pot procedure in good yields. The structures of products were confirmed by ¹H NMR, ³¹P NMR, IR spectra, and elemental analyses. The bioassay results showed that some of them possess excellent anti–tobacco mosaic virus activities and exhibit higher inhibitory effects compared with that of the contrast drug 2,4‐dioxyhexahydro‐1,3,5‐triazine. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:97–101, 2001     

Electronic spectra and first‐order hyperpolarizability of 4‐(dicyanomethylene)‐2,6‐bis‐ (2′‐thiophene‐vinyl)‐pyran derivatives

On the basis of the ZINDO program, we have designed a program to calculate the first‐order hyperpolarizability β_ijk and β_μ according to the sum‐over‐states (SOS) expression. The first‐order hyperpolarizability of 4‐(dicyanomethylene)‐2,6‐bis‐(2′‐thiophene‐vinyl)‐pyran derivatives were studied. The calculated results were that the 4‐(dicyanomethylene)‐2,6‐bis‐(2′‐thiophene‐vinyl)‐pyran derivatives exhibit good nonlinearity with their β₀ values, which are slightly less than that of the corresponding 2,6‐bis‐styryl‐4‐(dicyanomethylene)‐pyran derivatives. It does not agree with the auxiliary donor–acceptor effects theory. The 4‐(dicyanomethylene)‐2,6‐bis‐(2′‐thiophene‐vinyl)‐pyran derivatives, having two low‐lying electronic excited states that contribute to the molecular hyperpolarizability in an additive manner, are good candidates as chromophores due to their high nonlinearities and good thermal stability. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 82: 65–72, 2001     

Synthesis of high molecular weight trans‐poly(9,9‐di‐n‐octylfluorene‐2,7‐vinylene) by the acyclic diene metathesis polymerization using molybdenum catalysts

High molecular weight trans‐poly(9,9‐di‐n‐octylfluorene‐2,7‐vinylene) was prepared under reduced pressure in the presence of a well‐defined Schrock‐type catalyst, Mo(CHCMe₂Ph)(N‐2,6‐Me₂C₆H₃)[OCMe(CF₃)₂]₂, in toluene. The effect of initial monomer concentration was found to be an important factor for preparing high molecular weight polymers with unimodal molecular weight distributions. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2463–2470, 2001     

Reactions of 5‐methylene‐1,3‐thiazolidine‐2‐thione and 5‐methylene‐2‐oxazolidinone with isocyanates catalyzed by bases

5‐Methylene‐1,3‐thiazolidine‐2‐thione and 5‐methylene‐2‐oxazolidinone can react with isocyanates to give the corresponding condensed urethanes in high yields in the presence of organic or inorganic bases under mild reaction conditions. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:610–616, 2001     

Synthesis,antitumor activity and crystal structure of the triphenyltin derivative of exo‐7‐oxa‐bicyclo[2,2,1]hept‐5‐ene‐3‐N‐p‐tolylamide‐2‐acid

The synthesis and crystal structure of­Ph₃SnO₂CCHCHCH:CHCH(O)CHCONHC₆H₄­CH₃·CH₂Cl₂ are reported. The monomer units­are bridged by the carbonyl oxygen of the amide group, thus forming a polymer in which each tin atom is best described as having a distorted five‐coordinate geometry. There is a relatively strong intramolecular hydrogen bond between the amide hydrogen and the ether oxygen. The in vitro antitumor activities of the title compound against HL‐60, BGC‐823, Bel‐7402, SKOV3, KB and Hela tumor lines are reported. The title compound shows a distinct advantage when the metal (tin) is introduced into the acid.Copyright © 2001 John Wiley & Sons, Ltd.