"Phosphorus, Sulfur, and Silicon and the Related Elements"

doi: 10.1080/10426509108233918pmid: N/A

Abstract This is a scanned image of the original Editorial Board page(s) for this issue.

Shi, Min; Yamamoto, Kiichi; Okamoto, Yoshiki; Takamuku, Setsuo

doi: 10.1080/10426509108233919pmid: N/A

Abstract Upon. UV excitation in methanol, some diaryl esters of alkyl- or alkenylphosphonates underwent an elimination of two aryl groups to give biaryls and the corresponding alkyl- or alkenylphosphonic acids. Tris(4-methoxyphenyl) phosphite also underwent a similar elimination to give 4,4′-dimethoxybiphenyl and 4-methoxyphenyl phosphonate. This interesting biaryl elimination was confirmed to proceed via a singlet intramolecular excimer by means of fluorescence spectra and Stern-Volmer analysis.

Scovill, John P.

doi: 10.1080/10426509108233920pmid: N/A

Abstract Thiosemicarbazones of α-(N)-heterocyclic ketones and aldehydes possess a broad spectrum of potentially useful chemotherapeutic activities. Thus, the antimalarial, antibacterial, and antiviral properties of this class have been explored by Klayman, et al.1 The antileishmanial activity of a series of acetyl β-carboline thiosemicarbazones was recently described by Dodd and coworkers .2 The α-(N)-heterocyclic thiosemicarbazones act as tridentate ligands for transition metals3; this property has been implicated in their biological mechanism of action.4 The synthesis thiosemicarbazone-transition metal complexes and the spectroscopic investigation of structure and bonding in these complexes is being actively pursued 5 In order to facilitate these investigations, an improved method of synthesizing thiosemicarbones is desirable. Such a synthesis should be efficient (high yield), general (afford thiosemicarbazones of N4-monosubstitution or N4,N4-disubstitution patterns), safe (avoids toxic or unpleasant reagents and byproducts) and direct (a single step reaction which does not require the isolation of any intermediates). Klayman and Lin described the preparation of a variety of N4-mono and N4,N4-disubstituted thiosemicarbazones by the displacement of the dimethylamino function of the corresponding thiosemicarbazones by a primary or secondary amine.6 Thus, refluxing a solution of benzaldehyde 4,4-dimethyl-3-thiosemicarbazone (A) in acetonitrile (bp 82°C) for 6 h with two equivalents of aniline gave a 63% yield of benzaldehyde 4-phenyl-3-thiosemicarbazide (B). When the thiosemicarbazone substrate bore a hydrogen atom as an N4-substitutient, low yields (ca. 20%) of thiosemicarbazones could only be obtained under forcing conditions (24 h at 109°C in toluene). This clearly established the requirement for a secondary amine as a leaving group for facile transamination at the thiocarbonyl carbon atom. With this observation in mind, the reaction might be improved further by the substitution of a phenylmethylamino group for a dimethylamino group. Substitution of the electron withdrawing pheny group for one of the methyl groups should enhance the electrophilicity of the thiocarbonyl group. Furthermore, the aromatic amine, being a weaker base, ought to serve as a better leaving group. In this communication, I describe the facile preparation of thiosemicarbazides (1) by transamination of 4-methyl-4-phenyl-3-thiosemicarbazide (la), and thiosemicarbazones (2), by trans-amination of l a in the presence of the requisite aldehyde or ketone.

Kawashima, Takayuki; Yuzawa, Yorrou; Inamoto, Naoki

doi: 10.1080/10426509108233921pmid: N/A

Abstract The title reaction was investigated from the following two approaches; direct addition reaction of α-metallo derivatives of methyl-l-naphthylphenylphosphine oxide with benzaldehyde and reduction of the corresponding 2-oxoalkylphosphine oxide. The diastereomer ratio was determined by 31P NMR spectroscopy. The major diastereomer was (R,S)- or (S,R)-3, however, the reverse result was obtained only when diisobutylaluminum hydride was used as a reducing reagent. Transition state models were proposed in order to explain the stereochemistry.

Wieczorek, Wanda; Radkiewicz, Stanisław; Janczewski, Marian

doi: 10.1080/10426509108233922pmid: N/A

Abstract Using single crystal X-ray diffraction technique the R configuration has been assigned to a (+)2-(3′nitrobenzylsulfinyl)-benzoic acid. In the molecule an extended chain C8‒S‒Cl‒C2 is observed. Both phenyl rings lie on almost one plane. O1 and O5 atoms are involved in attractive interactions.

Causse, J. E.; Ibrahim, S.; Plenat, F.; Cristau, H. J.

doi: 10.1080/10426509108233923pmid: N/A

Abstract The application of desorption and direct inlet with electron impact and chemical ionization mass spectrometry of some 2-chloroethyl phosphonates related to etephon is described. Comparison of these methods showed that there are highly useful for obtaining: 1) adduct ions, especially protonated molecular ions: chemical ionization. 2) significant fragment ions: methane and electron impact ionization. Interpretation of spectra, based on the considerable analogy between the different structures of the phosphonates is described in this work. A choice between EI and CI mass spectrometry with either direct inlet or desorption technics, depending on the volatility of the compounds and the purpose of analysis, is done. The low fragmentation obtained by ammonia chemical ionization was used to analyze different mixtures of phosphonates.

Abdou, Wafaa M.; Ganoub, Neven A. F.

doi: 10.1080/10426509108233924pmid: N/A

Abstract Dibenzoylmethane dibromide (5) and 1,3-indandione dibromide (6) react with ylide-phosphoranes 1a‒c to give the α,β-unsaturated esters 10 and 13, respectively. All intermediates are isolated and identified. Structures 10 and 13 as well as the intermediates were confirmed by compatible analytical and spectroscopic results.

Cremlyn, Richard J.; Swinbourne, Frederick J.; Graham, Stephen; Cavaleiro, José A. S.; Domingues, Fernando J.; Dias, Maribel

doi: 10.1080/10426509108233925pmid: N/A

Abstract Benzaldehyde- and o-, m-, p-anisaldehyde azines; thiophene-2-carboxaldehyde, and biphenyl-4-carboxaldehyde azines (1-8) reacted with excess chlorosulfonic acid to give the disulphonyl chlorides (1a-8a). These were condensed with amines and hydrazine to give 27 derivatives, (Table 1) for biocidal evaluation. The orientation of sulfonation is discussed in relation to the stereoelectronic factors and the spectral data. Attempted chlorosulfonation of furan-2-carboxaldehyde azine (9) gave an impure product which could not be clearly characterized as the morpholidate derivative.

Głowacki, Zdzisław; Hoffmann, Maria; Topolski, Marek; Rachoń, Janusz

doi: 10.1080/10426509108233926pmid: N/A

Abstract 31P chemical shifts are reported for twenty aminoalkylphosphonic acids (APAs), nine 1-hydroxyalkyl phosphonic (HPAs) and six phosphonic acids (PAs). The protonation shifts and the substituent-induced effects (SCSs) of the amino and hydroxyl groups on the 31P NMR and α-carbon 13C NMR chemical shifts were calculated and discussed. Substituent shielding effects on phosphorus nucleus and deshielding effects on α-carbon are observed for both groups. Amino shielding effect on phosphorus nucleus is the sum of two interactions: 1) electron-withdrawing substituent effect propagated along the carbon chain, 2) hydrogen bonding and coulombic attaction between groups in the zwitterion forms. Both imply the increasing contribution of a P˭O resonance structure leading to the upfield S(P). Good linear correlation exist between chemical shifts of 1-hydroxyalkylphosphonic acids and the respective values of analogously constituted 1-aminoalkylphosphonic acids.

Kandeel, Maymona M.

doi: 10.1080/10426509108233927pmid: N/A

Abstract 2-Amino-6 (p-nitrophenylthio)benzthiazol (1) reacted with carbon disulfide in the presence of aqueous sodium hydroxide in N,N-dimethylformamide as solvent, to form the sodium salt of the dithiocarbon imidic acid. Without further purification, this salt was alkylated with sodium chloroacetate and treated with HCl to give the corresponding thiazolidinone (2). The thiazolidinone (2) underwent oxidation to the corresponding sulfone (3) when treated with AcOH/H2O2 and condensed easily with aromatic aldehydes, to give the corresponding 5-arylidinethiazolidinones (4), which after oxidation with H2O2,/ AcOH gave the sulfones (7). Sulfone (3), condensed with aromatic aldehydes, led to the same com pounds (7). Thiazolidinone (2) reacted with either one or two equivalents of an aromatic amine pro ducing compounds 5 and 6, respectively. The latter were oxidized with H2O,/AcOH to give the sulfones 8 and 9.