Essam Kh. Ahmed

Update survey on aroyl substituted thioureas and their applications

The literature on synthesis and applications of aroyl substituted thioureas is updated to 2006. Emphasis is placed on the relationship of structural features of the thioureas to their applications, which are in such diverse areas as the trace analysis of metals, materials science and agriculture. The review contains 93 references.

NEW HETERO-ANNELATION REACTIONS USING N-BIS-(METHYLTHIO)-METHYLENE-AMINO AND RELATED REAGENTS

SummaryReaction of acyclic (B1–3) and cyclic (R4–5)BMMA (=N-[bis-(methylthio)-methylene]-amino) reagents withGewald-type thiophene derivatives (2,3) led to annelation of pyrimidine moieties. Thus, linear thiazolo- or thiazino- and pyrrolo-, pyrido- or azepino-fused thiopyrano[4′,3′:4,5]thieno-[2,3-d]pyrimidines (5 and6) as well as the angular imidazo-fused thiopyrano[4′,3′:4,5]thieno-[2,3-d]pyrimidine8 were easily obtained from one-pot reactions in good yields.ZusammenfassungUmsetzung von acyclischen (R1–3) und cyclischen (R4–5)BMMA-Reagenzien (BMMA=N-[bis-(Methylthio)-methylen]-amino)mitGewald-artigen Thiophenderivaten (2,3) führte zur Anellierung von Pyrimidinringen. Auf diese Weise konnten linear kondensierte Thiazolo- oder Thiazino- und Pyrrolo-, Pyrido- oder Azepinothiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidine (5 und6) sowie das angulär imidazo-anellierte Thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin8 in guten Ausbeuten auf direkte Weise in Eintopfreaktionen erhalten werden.

A convenient and efficient method for the synthesis of benzo- and naphthothiazolediones

A series of benzo- and naphthothiazolediones have been synthesized by the reactions of N-substituted thioureas with π-deficient quinones. The products were obtained by the reaction of N-aroylphenylthioureas with 2,3,5,6-tetracholoro-1,4-benzoquinone, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and 2,3-dichloro-1,4-naphthoquinone.

Synthesis of dihydrothiopyrano[3,4-c]pyridines and of fusion products thereof

SummaryReaction of the 6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrile derivative2 with α-halogeno-carbonyl compounds gave the O-substituted intermediates3a–d which on treatment with base were converted into the furo[2,3-b]thiopyrano[4,3-d]pyridines4a–d by fusion of a furan moiety. Cyclization of the corresponding ester4d led to fusion of a pyrimidine ring, thus yielding the tetracyclic product8 as well as its N-substituted derivatives9a–e. Target compounds2–9 were derived from the three novel heterocyclic parent systemsA–C.ZusammenfassungReaktion des 6-Hydroxy-thiopyrano[3,4-c]pyridin-5-carbonsäurenitril — Derivates2 mit α-Halogencarbonylverbindungen führte über die entsprechenden O-substituierten Zwischenprodukte3a–d durch Furan-Anellierungen zu den Furo[2,3-b]thiopyrano[4,3-d]pyridin — Derivaten4a–d. Cyclisierung des entsprechenden Esters4d gab unter Pyrimidin-Anellierung das tetracyclische Produkt8 sowie dessen N-Substitutionsprodukte9a–e. Die Zielverbindungen2–9 leiten sich von den drei neuen heterocyclischen GrundkörpernA–C ab.

Oxidation of aroylthioureas during their reactions with 2,3-diphenylcyclopropenone resulting in (E/Z)-3-(aroylthioureido)-2-phenylcinnamic acids

Isolated (E/Z)-3-(aroylthioureido)-2-phenylcinnamic acids have been obtained from the reactions of N-substituted-aroylthioureas with 2,3-diphenylcyclopropenone in acetic acid. The abnormal behavior of the reaction was described as due to nucleophilic addition of N 3 followed by hydrolysis, ring opening and oxidation processes.

A Straightforward and Mild Method of Tethering Monosaccharides to Thieno(2,3-d)pyrimidinones via the Copper(I)-catalyzed Azide-Alkyne 'Click Chemistry'

A mild and versatile method based on Cu(I)-catalyzed [3+2] cycloaddition (Meldal-Sharpless reaction) was developed to tether biomolecules, such as monosacharides or lipophylic azides, to alkyne functions of spirobenzo[b]thieno[2,3-d]pyrimidine-1´-cyclohexane. The reactions are highlighted by their modularity and high efficiency with excellent yields in most cases. The products are interesting precursors for a variety of applications. Graphical Abstract A Straightforward and Mild Method of Tethering Monosaccharides to Thieno[2,3-d]pyrimidinones via the Copper(I)-catalyzed Azide-Alkyne ‘Click Chemistry’

FUSED QUINOLINE HETEROCYCLES IV. FIRST SYNTHESIS OF FOUR HETEROCYCLIC RING SYSTEMS OF lH-5-THIA-l,2,3,6-TETRA-AZAACEPHENANTHRYLENES AND 1H-5-THIA-l,3,6-TRIAZAACEPHENANTHRYLENES

Abstract The synthesis of some novel fused tetracyclic compounds such as IH-5-thia-l,2,3,6-tetraa-zaacephenanthrylenes and 1H-5-thia- l,3,6-triaza;lcephenanthrylenes containing quinoline ring system have been reported.

New Polymer Syntheses Part 60: A Facile Synthetic Route to Polyamides Based on Thieno[2,3-b]thiophene and Their Corrosion Inhibition Behavior

Polyamides containing thieno[2,3-b]thiophene moiety were prepared via a simple polycondensation reaction of the diaminothieno[2,3-b]thiophene monomer 1a with different kinds of diacid chlorides (including oxalyl, adipoyl, sebacoyl, isophthaloyl, terephthaloyl, 4,4′-azodibenzoyl, 3,3′-azodibenzoyl, p-phenylene diacryloyl) in the presence of LiCl and NMP as a solvent through lowtemperature solution polycondensation. The chemical structures of model compound and synthesized polyamides were confirmed by FTIR, nuclear magnetic resonance spectroscopy (including 1H-NMR and 13C-NMR) and elemental analysis. In addition, the thermal stability, crystallinity structure and surface morphology of synthesized polyamides were characterized via thermogravametric analysis (TGA), wide-angle X-ray diffraction analysis (WAXD) and scanning electron microscopy (SEM). Also, the corrosion inhibition behavior of selected examples of polyamides was investigated; the inhibitive effect of the investigated polymers for carbon steel in 1.0 mol·L−1 HCl was studied using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) methods. PDP results displayed that the polyamides containing thieno[2,3-b]thiophene moiety can be as mixed-type inhibitors. The inhibition efficiency (P, %) was found to be in the range from 67.13% to 96.01%. There is an increase in P by the synthesized polymers in comparison to the starting monomer. The adsorption of these polymers was found to obey Langmuir adsorption isotherm.

Synthesis and evaluation of anticancer and PDE 5 inhibitory activity of spiro-substituted quinazolin-4-ones

A series of novel spiro-substituted 2,3-dihydroquinazolin-4(1H)-ones was synthesized and structurally confirmed by spectral analysis, screened for their anticancer activity at a concentration of 10 μΜ against a panel of 56 cell lines derived from nine different types of cancers, including leukemia, melanoma, lung, colon, CNS, ovarian, renal, prostate, and breast cancers. The synthesized compounds screened for their PDE 5 inhibitory activity and it showed encouraged activity compared to sildenafil.Graphical abstract

Crystal structure of (4-meth-oxy-phen-yl)[(4-meth-oxy-phen-yl)phospho-nato]dioxidophosphate(1-) 2-amino-6-benzyl-3-eth-oxy-carbon-yl-4,5,6,7-tetra-hydro-thieno[2,3-c]pyridin-6-ium.

The asymmetric unit of the title molecular salt, C17H21N2O2S+·C14H15O7P2 −, comprises two cations and two anions. Each cation features an intramolecular N—H⋯O hydrogen bond, which closes an S(6) ring; in each case the hydropyridine ring adopts a half-chair conformation. In the anions, the dihedral angles between the aromatic rings are 64.1 (2) and 54.9 (2)°. In each case, the diphosphate groups are close to eclipsed [C—P⋯P—C pseudo-torsion angles = 11.6 (2) and −19.3 (2)°]. One of the methoxy groups in each anion is disordered over two orientations in a 0.539 (18):0.461 (18) ratio in one anion and 0.82 (2):0.18 (2) in the other. In the crystal, O—H⋯O and N—H⋯O hydrogen bonds link the components into [100] chains. Numerous C—H⋯O interactions cross-link the chains into a three-dimensional network.