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ملخص الأوراق العلمية المنشورة

 

 

Dibromotriphenylphosphorane Promoted Synthesis of Condensed Heterocyclic Systems from Aromatic Diamines

Hamad Z. Alkhathlan and Hans Zimmer

   J. Heterocyclic Chem., 1988, 25, 1047. 

Abstract

A new and rather widely applicable method for the synthesis of a number of tri, tetra and pentacyclic compounds from ortho-aminodiacylarylimides and dibromotriphenylphosphorane via an intramolecular cyclization is reported. A mechanism for this reaction is proposed. 

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Novel Heterocyclic Compounds via Aza and Bis-Aza-Wittig Reactions

Hamad Z. Alkhathlan and Hamed A. Al-Lohedan

Phosphorus, Sulfur and Silicon, 1991, 63, 301

Abstract

Two quinoxaline derivatives, 1 and 2, were prepared via a bis-aza-Wittig reaction when the suitable aromatic diamine was treated with (MeO)3PBr2/Et3N followed by the addition of benzil. Also, two additional novel heterocyclic compounds, 4 and 6 were prepared via an intramolecular aza-Wittig reaction.

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Essential Oils of Some Saudi Pulicaria and Artemisia species

H. Z.  Alkhathlan, M. Al-Zoman, R. M. Basha, A. A. Mousa and H. M. G. Al-Hazimi Oriental  J. Chem., 1991, 7, 204

                                                       Abstract

The constituents of the essential oils of two Pulicaria species are reported here for the first time. In addition, the oils of a Pulicaria and five Artemisia species have been analyzed and compared with previous studies.

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Application of Phosphorus, Arsenic and Antimony Reagents in the Synthesis of Heterocyclic Compounds

Hamad Z. Alkhathlan and Hamed A. Al-Lohedan

Phosphorus, Sulfur and  Silicon, 1991, 61, 367

Abstract

The ability of different reagents of the type R3XBr2 where R are various alkyl, alkoxide, phenyl and phenoxide groups and X is P, As and Sb to promote an intramolecular cyclization of suitably substituted aromatic diamines has been investigated. The type of R group and X was found to have a great influence on the ability of these reagents to promote this type of cyclization.  Best results were obtained when R= OMe and

X= P.

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Studies on the Staudinger Reaction

Hamad Z. Alkhathlan

Oriental J. Chem., 1992, 6, 50

Abstract

Different reagents of the type R3X (where R= various groups, X= P, As, Sb) were tested in their ability to promote an intramolecular aza-Wittig reaction. These reagents were reacted with a suitable azide and the yields of the cyclized products were calculated.

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Synthesis and Spectroscopic Studies of Novel Quinoline Derivatives

Hamad Z. Alkhathlan

Synth. Commun., 1992, 22, 2659

                                                       Abstract

An intramolecular Wittig reaction of some substituted aminoacetophenones was used    for the synthesis of novel quinoline derivatives. In addition, the base induced cyclization of the aminoacetophenones was investigated. The IR and NMR spectra of the quinoline derivatives are reported. 

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Novel Approach to Pyrrolo[1,2-a]quinoline-1,5-diones

Hamad Z. Alkhathlan

J. Chem. Res., 1992, (S) 260, (M) 1984 

Abstract

The condensation of 2-aminoacetophenone with acid anhydrides is investigated. Different fused 4-quinolones derivatives were prepared in one step via this condensation. In addition, different N-substituted imides were also obtained. 

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Sesquiterpene Lactones from Artemisia Species

Hamad Z. Alkhathlan, A. A. Mousa and H. M. G. Al-Hazimi

J. Chem. Soc. Pak., 1992, 14, 151 

Abstract

Naturally occurring sesquiterpene lactones from Artemisia species which appeared in the literature during the last six years (1984-1989) have been reviewed.  

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Chemistry of Various Pulicaria Species

Hassan M.G. Al-Hazimi and Hamad Z. Alkhathlan

J. Chem. Soc. Pak., 1992, 14, 233

 Abstract

Secondary metabolites from various Pulicaria species up to the end of 1990 have been reviewed. 

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A New Diterpene and Flavonoids from Pulicaria somalensis

Hassan M. G. Al-Hazimi and Hamad Z. Alkhathlan

J. King Saud Univ. (Science), 1993, 5, 141 

Abstract

A new diterpene of clerodane type and three known methylated flavones (chrysosplenol D, chrysoplenetin and casticin) have been isolated from the aerial parts of Pulicaria somalensis and characterized by spectroscopic methods. chrysoplenetin and casticin have been isolated from the Pulicaria genus for the fires time. 

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Spectroscopic Studies of Benzimidazole, Quinoxaline and Quinoline Derivatives

Hamad Z. Alkhathlan and Hamed A. Al-Lohedan

J. Chem. Res., 1995, (S) 10, (M) 201 

 Abstract

Four fused benzimidazoles, two quinoxalines and two fused quinoline derivatives were studied with respect to their mass, NMR and IR spectra; the compounds were chosen in order to compare the effect of the size of the hetero ring and the presence of C=N and C=O on their spectral behaviour. 

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Naturally Occuring Non-Alkaloidal Phenanthrenes

Hassan M.G. Al-Hazimi and Hamad Z. Alkhathlan

J. Saudi Chem. Soc., 1997, 1, 47 

Abstract

In this review, an attempt has been made to list all new non-alkaloidal phenanthrenoids which have isolated from the different plant families. The antimicrobial activities of those compounds is included. 

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Stilbenes and Bibenzyls in Higher Plants

Hassan M.G. Al-Hazimi and Hamad Z.   Alkhathlan

J. King Saud Univ. (Science), 1997, 9, 161

Abstract

Stilbenes and their dihydroderivatives, bibenzyls, which have been isolated from higher plants up to the end of 1994 are reviewed. 

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Chemical Constituents of T. aurilactum, R. vesicarius, P. orientalis, P. somalensis and A. abyssinica Grown in Saudi Arabia

Hamad Z. Alkhathlan and Hassan M.G. Al-Hazimi

J. Chem. Soc. Pak, 1996, 18, 309 

Abstract

The volatile oils of five plants, Tripleurospermum aurilactum, Rumex vesicarius, Pulicaria orientalis, P. somalensis and Artemisia abysinica were collected using steam distillation and their constituents were analyzed bu GS/MS. The first two plants are being studied for the first time. In addition, a further study on the chemical constituents of the third one is reported. 

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Naturally Occuring Iridoids During the Period 1990-1993

.Hassan M.G. Al-Hazimi and Hamad Z. Alkhathlan

J. Chem. Soc. Pak, 1996, 18, 336 

Abstract

New iridoids, secoiridoids, bis-iridoids and other miscellaneous iridoids isolated during the period 1990-1993, together with their botanical sources are listed. Furthermore, the re-isolated iridoids during the period covered by the present review are also given. 

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An Approach Towards Fused Thieno[3,2-b]pyridines

Hamad Z. Alkhathlan

Heterocycles, 1997, 45, 45 

Abstract

A series of fused thieno[3,2-b]pyridines was prepared via the condensation of substituted 2-acetyl-3-aminothiophenes and acid anhydrides. In addition, selected examples of these compounds were prepared via an intramolecular Wittig reaction. 

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Chemical Investigation on the Leaves of Hibiscus furcatus

T. K. Bindu, A. Saidutty, H. Z. Alkhathlan and P. M. Shafi

Asian  J. of Chem., 1997, 9, 734 

Abstract

The petroleum ether (60-80°C) extract of the leaves of Hibiscus furcatus yielded five components. They were identified to be friedelin, ß-sitosterol, taraxerol, a mixture of

 n-alkanes in the C30-C34 range and a mixture of n-alkanols in the C28-C34  range by chemical and physical methods. 

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Synthesis of 2,3-Disubstituted 4-Oxoquinolines and 3-Substituted Fused 4-Oxoquinolines

Hamad Z. Alkhathlan  and  Khalid A. Al-Farhan

Heterocycles, 1998, 48, 641 

Abstract

Seven 2,3-disubstituted 4-oxoquinolines were prepared via two methods. In the first one 2,3-disubstituted 4-oxoquinolines were prepared via the condensation of 2-amino-œ-cyanoacetophenone with substituted phthalic anhydrides, while in the second method the fused isoindolo[2,1-a]quinolines and pyrolo[1,2-a]quinoline were first prepared and then converted to 4-oxoquinolines. X-ray crystal structure analysis of ethyl 2-[3-cyano-4-oxo-2-quinolyl]benzoate is reported. 

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Radical Copolymerization and Characterization of N-(tri-n-butyltin)Maleimide Monomer with Styrene, Methacrylate and N-vinyl-2-pyrrolidinone

Nayef S. Al-Muaikel, Salem S. Al-Diab and Hamad Z. Alkhathlan

Asian J. of Chem., 1999, 11, 1259 

Abstract

Three types of novel organotin polymers from polymerization of new organotin monomer N-(tri-n-butyltin)maleimide with styrene, methylmethacrylate and N-vinyl-2-pyrrolidinone in bulk at 65°C. Using 2,2-azo-bis-isobutyronitrile (AIBN) as initiator. Characterization of of the prepared copolymers was accomplished by IR, 1H-NMR spectra and elemental analysis. All the copolymers dissolved readily at room temperature in most polar aprotic solvents. The thermal stability of the polymers was evaluated by TGA and DSC measurements.

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Synthesis of New Di-(tri-n-butyltin)citraconate and its Copolymer

Nayef S. Al-Muaikel, Salem S. Al-Diab and Hamad Z. Alkhathlan

J. King Saud Univ. (Science), 2000, 12, 25 

Abstract

Anew monomer of Di(tri-n-butyltin)citraconate has been synthesized by the reaction of citraconic anhydride and bis(tri-n-butyltin)oxide. This monomer was copolymerized with styrene using 2,2-azo-bis-isobutyronitrile (AIBN) as a free radical initiator. The monomer and copolymer were identified by elemental analysis, IR and NMR spectroscopy. 

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Synthesis and Characterization of Novel Organotin Monomer of N-(tri-n-butyltin)Maleimide, Homopolymerization  and Copolymerization with Styrene

Nayef S. Al-Muaikel, Salem S. Al-Diab , Hamad Z. Alkhathlan and Ahmed Al-Obied

 J. Saudi Chem. Soc., 2000, 4, 43

 Abstract

New monomer, N-(tri-n-butyltin)maleimide N-(TBTM) wes prepared by the reaction of maleimide (MI) with tri-n-butyltinoxide (TBTO) in the presence of acetone as a solvent. The prepared monomer was copolymerized with styrene (ST) using benzene as solvent with 1 mol.% of 2,2-azo-bis-isobutyronitrile (AIBN) as free radical initiator. The structure of new monomer, homopolymer and copolymer have been characterized by elemental analysis, IR and NMR,  the molecular weights of the homopolymer and copolymer have been established by GPC. 

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Naurally Occuring Pterocarpanoids and Related Compounds

 H. M.G. Al-Hazimi and Hamad Z. Alkhathlan

J. King Saud Univ. (Science), 2000, 12, 93 

Abstract

In the present review an effort has been made to list all pterocarpanoids and coumestans which have been isolated from various plants belonging to the plant family Leguminosae (Fabaceae) up to mid-1998. The antimicrobial activities as well as the biosynthesis pathways of the compounds are briefly included. 

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Condensation Products of 3-Aminothiophenes with Acid Anhydrides

Hamad Z. Alkhathlan

Asian J. Chem., 2002, 14, 1427 

Abstract

Condensation of substituted 3-aminothiophenes with six different carboxylic acid anhydrides resulted in the formation of three types of products: N-(substituted thienyl)imides, substituted carboxylic acids and fused thieno[3,2-b]pyridines. The IR, NMR and MS spectra of these compounds are discussed. 

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Synthesis and X-ray crystal Structures of Novel Spiro 1,3-Benzoxazine Dimers

H. Z. Alkhathlan, M. A. Al-Saad, H. M. Al-Hazimi, K. A. Al-Farhan and

A. A. Mousa

J. Chem. Res.  2002, (S) 473, (M) 1023

 Abstract

Novel spiro 1,3-benzoxazine dimmers are obtained when hydrazones of

2-hydroxyacetophenone are treated with triphosgene. An X-ray crystal structure and the NMR and MS spectra of these new compounds are reported and discussed.

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Quinazoline, Pyrazolo[1,5-c]quinazoline and Spiro Quinazoline Dimers from the Reaction of 2-Aminoacetophenene Hydrazones with Triphosgene

H. Z. Alkhathlan, M. A. Al-Saad, H. M. Al-Hazimi, K. A. Al-Farhan and

A. A. Mousa

J. Chem. Res.  2002, (S) 587, (M) 1201 

Abstract

The reaction of hydrazones of 2-aminoacetophenone with triphosgene in dichloromethane or benzene in the presence of triethylamine gave quinazolines, pyrazolo[1,5-c]quinazoline and spiro quinazoline dimmers. The latter compounds are being reported for the first time. In addition, a 4,4-disubstituted quinazoline derivative is prepared and its X-ray crystal structure is reported. 

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Synthesis of 4-alkoxy-4-methyl- and 4-alkoxy-4-fluoromethyl-1,3-benzoxazinones

Hamad Z. Alkhathlan

Tetrahedron, 2003, 59, 8163

 Abstract

Cyclization of 2-hydroxyacetophenone hydrazones with triphosgene resulted in the formation of 4-methylene-1,3-benzoxazinones. These compounds were converted to 4-alkoxy-4-methyl-1,3-benzoxazinones and 4-fluoromethyl-4-methyl-1,3-benzoxazinones upon treatment with alcohols under refluxing conditions and F-TEDA-BF4 in acetonitrile and methanol, respectively.

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A One-Pot Synthesis of 1,3-Benzoxazines

Hamad Z. Alkhathlan

Synth. Commun., 2004, 34, 71

Abstract

Reaction of substituted 2-hydroxyacetophenones with amines under microwave irradiation (MW) gave the corresponding imines (Schiff bases) which were treated without separation or identification with triphosgene to give 4-methylene-1,3-benzoxazines in good yields. 

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Synthesis, Spectroscopic Studies and X-Ray Crystal Structure of

                     N-Heteryliminophosphoranes                          

H. Z. Alkhathlan, M. A. Al-Jaradah, K. A. Al-Farhan and A. A. Mousa

Phosphorus, Sulfur and  Silicon, 2004, 179, 1

 

Abstract

N-[2-(œ-Bromoacetyl)phenyl]imides (prepared in two steps from 2-aminoacetophenone) gave upon treatment with sodium azide fused azidoquinolines via an intamolecular cyclization. Reaction of the above azides with phosphines gave N-heteryliminophosphoranes. The IR, 1H-, 13C-, and 31P-NMR and MS spectra of these compounds as well as the X-ray crystal structure of two of them is reported.

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Three 2-(2-Phenylethyl)chromones and Two Terpenes from Agarwood

H. Z. Alkhathlan, H. M. Al-Hazimi, F. S. Al-Dhalaan and A. A. Mousa

Natural Product Research, 2005, 19, 367 

Abstract

A new chromone, 7,8-dimethoxy-2-[2-(3'-acetoxyphenyl)ethyl]chromone (1) was isolated from an acetone extract of the Cambodian agarwood along with two known chromones, 6-methoxy-2-(2-phenylethyl)chromone (2) and 6,7-dimethoxy-2-(2-phenylethyl)chromone (3). In addition, an abietane ester (4) and the sesquiterpene dehydrofukinone (5) were isolated from the agarwood oil of the same origin. Structural elucidation of all isolated compounds was made on IR, 1H-, and 13C-NMR spectroscopic data.

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Essential Oils of A. Factorovskyi, K. Linearis, C. Arvensis, P. Babylonica, P. Cyanocarpa, L. Nucicaulis and R. Epapposum

 S. A. Al-Mazroa, L. H. Al-Wahaibi, A. A. Mousa and H. Z. Alkhathlan

 J. Saudi Chem. Soc., 2005, 9, 693 

Abstract

The constituents of the essential oils of A. factorovskyi, K. linearis, C. arvensis, P. babylonica, P. cyanocarpa, L. nudicaulis and R. epapposum, all belonging to the family Compositae, are reported. The majority of these plants are studied herein for the first time.