SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF INSIGNIN AND ITS 8-METHOXY- AND 6-DEMETHOXY DERIVATIVES

A short and efficient synthesis of insignin (8-hydroxy-6-methoxy-3-heptyl- isocoumarin) (1), a metabolite of natural lichens, has been described. Reaction of 3,5-dimethoxyhomophthalic anhydride (2) with octanoyl chloride in the presence of 1,1,3,3-tetramethylguanidine (TMG) and triethyl amine afforded the 6,8-dimethoxy-3-heptylisocoumarin (3) in high yield. Regioselective demethylation of the latter using anhydrous aluminum chloride furnished the 8-hydroxy-6-methoxy-3-heptylisocoumarin (1) whereas, the complete demethylation of (3) yielded 6,8-dihydroxy-3-heptylisocoumarin (4). The isocoumarins (1, 3, and 4) were examined in vitro for antibacterial activity and were shown to exhibit moderate activity. KEY WORDS: Isocoumarin, Insignin, Antibacterial, Porpidia glaucophaea, Haematomma pachycarpum, 3,5-Dimethoxyhomophthalic anhydride Bull. Chem. Soc. Ethiop. 2006, 20(1), 83-87

Synthesis and Crystal Structure of 1-(3-fluorophenyl)-3-(3,4,5-trimethoxybenzoyl)thiourea

The title thiourea was synthesized by reaction of 3,4,5-trimethoxybenzoyl isothiocyante with 3-fluoroaniline. The 3,4,5-trimethoxybenzoyl isothiocyante was produced in situ by reaction of 3,4,5-trimethoxybenzoyl chloride with ammonium thiocyanate in dry acetonitrile. The structure was confirmed by the spectroscopic, elemental analysis and single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 13.0966(9), b = 16.6460(13), c = 7.8448(5), β = 106.721(5)°, V 1637.9(2) ų, Z = 4

Methyl 2-oxo-2H-chromene-3-carboxylate

The title compound, C11H8O4, features an almost planar molecule (r.m.s. deviation = 0.033 Å for all non-H atoms). In the crystal, the molecules are linked via C-H...O hydrogen bonds, forming two-dimensional networks lying parallel to (1-21)

2-Chloro-N-(4-meth­oxy­phen­yl)benzamide

In the title compound, C14H12ClNO2, the chloro- and meth­oxy-substituted benzene rings are close to orthogonal [dihedral angle = 79.20 (3)°]. These rings also make angles of 45.9 (3) and 33.5 (3)° with the amide –CONH– unit. The meth­oxy substituent lies close to the meth­oxy­benzene ring plane, with a maximum deviation of 0.142 (3) Å for the methyl C atom. The N—H bond is anti to the 2-chloro substituent of the aniline ring. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds form C(4) chains augmented by a weak C—H⋯O inter­action involving an ortho H atom of the meth­oxy benzene ring that generates an R 2 1(6) motif. The chains stack the mol­ecules into columns down the b axis. Adjacent columns are linked by additional C—H⋯O and C—H⋯π contacts, generating a three-dimensional network

3,4,5-Trimeth­oxy-N-(2-methoxy­phen­yl)benzamide

In the title mol­ecule, C17H19NO5, the amide plane is oriented at an angle of 41.5 (3)° with respect to the 2-methoxy­benzene ring. The three meth­oxy groups lie almost in the plane of the aromatic rings to which they are attached [C—O—C—C torsion angles of of 0.7 (4), −13.4 (4) and 3.1 (4)°], whereas the meth­oxy group at the 4-position of the 3,4,5-trimethoxy­benzene ring is nearly perpendicularly oriented [C—O—C—C torsion angle of 103.9 (3)°]. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules into chains along [001]

N-(2-Methyl­phen­yl)-2-nitro­benzamide

In the title compound, C14H12N2O3, the dihedral angle between the two aromatic rings is 41.48 (5)°. The nitro group is twisted by 24.7 (3)° out of the plane of the aromatic ring to which it is attached. The mol­ecules are connected by N—H⋯O hydrogen bonds into chains running along the a axis

Synthesis, characterization and crystal structure of 1-(4-methylbenzoyl)-3-(4 aminosulfonylphenyl)thiourea

An efficient synthesis of the title compound, 1-(4-methylbenzoyl)-3-(4-aminosulfonyl phenyl)thiourea,  was carried out by reaction of 4-methylbenzoyl chloride with potassium thiocyanate in acetone to afford 4-methylbenzoyl isothiocyanate in situ followed by treatment with sulfanilamide. The structure was confirmed by spectroscopic data and elemental analyses. The molecular structure was determined from single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P21/n with unit cell dimensions of a = 4.8116(9) Å, b = 17.150(3) Å, c = 18.677(3) Å, γ = 96.487(4) °, and V = 1531.4(5) Å3

1-(2-Fluoro­phen­yl)-6,7-dimethoxy­isochroman

In the title compound, C17H17FO3, the benzene ring of the isochroman unit is inclined at 84.96 (7)° to the fluoro­benzene ring plane, and the pyran ring adopts a half-boat conformation. In the crystal structure, C—H⋯O hydrogen bonds link mol­ecules into rows along the c axis, while C—H⋯O inter­actions and C—H⋯F hydrogen bonds to the fluorine acceptor stack the mol­ecules down the b axis. In addition, the crystal structure exhibits a weak C—H⋯π inter­action between a methyl H atom of the meth­oxy group and the dimethoxy­benzene ring of an adjacent mol­ecule

A monoclinic polymorph of N-(3-chloro­phen­yl)benzamide

The title compound, C13H10ClNO, (I), is a polymorph of the structure, (II), first reported by Gowda et al. [Acta Cryst. (2008), E64, o462]. In the original report, the compound crystallized in the ortho­rhom­bic space group Pbca (Z = 8), whereas the structure reported here is monoclinic P21/c (Z = 4). The principal difference between the two forms lies in the relative orientations of the phenyl and benzene rings [dihedral angle = 8.90 (13)° for (I) and 61.0 (1)° for (II)]. The inclination of the amide –CONH– units to the benzoyl ring is more similar [15.8 (7)° for (I) and 18.2 (2)° for (II)]. In both forms, the N—H bonds are anti to the 3-chloro substituents of the aniline rings. In the crystal, inter­molecular N—H⋯O hydrogen bonds form C(4) chains along c. These chains are bolstered by weak C—H⋯O inter­actions that generate R 2 1(6) and R 2 1(7) ring motifs

An Empirical Investigation of Absorptive Capacity on Technology Transfer Effectiveness Through Organizational Innovation

Purpose:   Achieving technology transfer effectiveness (TTE) remains challenging in developing and underdeveloped economies to improve social infrastructures and develop economic systems. Bringing effectiveness in technology transfer is a complicated process for organizations that require improvement in their absorptive capacity (ACAP) and organizational innovation (OI). In the Information and communication technology (ICT) sector of Pakistan, technology transfer is ineffective due to a lack of ACAP and OI. This study aims to investigate the impact of ACAP and OI on TTE in the ICT sector of Pakistan.   Theoretical framework:   This study empirically investigated the relationship of ACAP and OI with TTE with underpinning organizational learning theory.   Design/methodology/approach:  A cross-sectional survey design was adapted for collecting data from 393 management representatives from 33 organizations of two main sub-sectors (Telecommunications and Information Technology) of the ICT sector of Pakistan. PLS-SEM was used for the reliability and validity measurement of research constructs. It also tested the hypothesized relationships between ACAP, OI, and TTE.   Findings:  This study confirmed the significant relationship of ACAP and OI with TTE. Further, the results also confirmed the mediation of OI between ACAP and TTE in the ICT sector of Pakistan.   Research, Practical & Social implications:  The implication of this research is to help government institutions and public and private sectors to develop mechanisms, economic policies, strategies, and business support for effective technology transfer in the ICT sector. This research model is also helpful for researchers and practitioners in its applicability in other industries, countries, and cross-cultural environments.   Originality/value:   Due to the lack of research in the ICT sector of Pakistan, this study empirically investigated the hypothesized significant relationships of ACAP and OI with TTE. This study also filled the research gap by evaluating the significant mediation of OI between ACAP and TTE and contributed to the body of knowledge