Saleh Mohammed Al-Mousawi

Enaminones in heterocyclic synthesis: a novel route to tetrahydropyrimidines, dihydropyridines, triacylbenzenes and naphthofurans under microwave irradiation.

Condensation of phthalimidoacetone (1) with DMFDMA (N,N-Dimethylformamide dimethyl acetal) has afforded enaminone 2. Refluxing 2 with equimolecular amounts of benzaldehyde and urea in acetic acid afforded a mixture of tetrahydropyrimidine 5 and the dihydropyridine 6. Compound 2 undergoes self-condensation on heating in acetic acid or under microwave irradiation in presence of acidic zeolite to give 1,3,5-triacylbenzene 9. Reacting enaminone 11a with naphthoquinone 15 afforded the naphthofuran 18. The possible formation of the aldehyde 19 was excluded based on an HMQC experiment, which revealed that the carbonyl carbon is not linked to any hydrogen.

STUDIES WITH CONDENSED AMINOTHIOPHENES : MICROWAVE ASSISTED CYCLOADDITION REACTIONS OF THIENO[3,4-d]-PYRIDAZINONE AND THIENO[3,4-c]QUINOLINONE

The arylformazane (2) was produced via coupling the α-oxoarylhydrazones (1) with aromatic diazonium salts. These formazane condensed readily with ethyl cyanoacetate to yield arylazopyridazinones (4) that reacted with sulphur in the presence of piperidine to yield the aminoazothienopyridazinone (5), the latter was reacted with electron poor olefins and acetylenes to yield aminoazophthalazines (8). Compound (8) was reacted with dimethylformamide dimethylacetal to yield amidine (9). Similarly aminothienoquinolinone (17) was reacted with electron poor olefins and acetylenes to yield aminophthalazines (20, 22a,b).

Recent developments in utility of green multi-component reactions for the efficient synthesis of polysubstituted pyrans, thiopyrans, pyridines, and pyrazoles

Developments made since 2010 in the utilization of multi-component reactions as green efficient methodologies for the synthesis of polysubstituted pyrans, thiopyrans, pyridines, and pyrazoles are reviewed and the mechanisms of these processes are discussed. Reference is made to classical older synthetic methods developed earlier in our laboratories.Graphical Abstract

Studies with malononitrile derivatives: synthesis and reactivity of 4-benzylpyrazole-3,5-diamine, 4-benzylisoxazole-3,5-diamine and thiazolidin-3-phenylpropanenitrile

Benzylmalononitrile 6 reacts with hydrazines, and hydroxylamine hydrochloride to yield the 4-benzylpyrazole-3,5-diamines 7 and 4-benzylisoxazole-3,5-diamine 9, respectively. Pyrazole-3,5-diamines 7 could be readily reacted with α,β-unsaturated nitriles to yield pyrazolo[1,5-a]pyrimidines 20. Benzylmalononitrile, also reacted with thioglycolic acid to yield tautomeric mixture of 2-(4-hydroxythiazol-2-yl)-3-phenylpropanenitrile 29 and 2-(4-oxothiazolidin-2-yl)-3-phenylpropanenitrile 30 that coupled with benzene diazonium chloride to yield 2-(4-oxo-5-(phenylhydrazono)-thiazolidin-2-ylidene)-3-phenylpropanenitrile31.

Disperse Dyes Based on Aminothiophenes: Their Dyeing Applications on Polyester Fabrics and Their Antimicrobial Activity

A series of monoazo disperse dyes derived from arylazothienopyridazines were synthesized. Fastness properties of dyed polyester samples were measured. Most of the dyed fabrics tested displayed excellent washing and perspiration fastness and moderate light fastness. Finally, the biological activity of the synthesized dyes against Gram positive bacteria, Gram negative bacteria and yeast were evaluated.

Green methodologies in organic synthesis: recent developments in our laboratories

The results of the studies carried out in our laboratories during the last 15 years, aimed at developing green methodologies for the synthesis of polyfunctionalized heteroaromatic substances, are surveyed. The results of the investigations demonstrate that green methodologies are not only less hazard than classical preparative methods but they also are more efficient and economical. For example, short reaction times and higher yields are observed for reactions in which conventional heating is replaced by microwave or ultrasound irradiation. The implementation of multicomponent reactions in green preparative routes also reduces the cost of carrying out the reactions because multiple separation and crystallization steps are avoided. In general, by employing the new green methodologies we have been able to produce a large number of polyfunctional aromatic substances in a highly efficient manner.

Azolyacetones as precursors to indoles and naphthofurans facilitated by microwave irradiation with simultaneous cooling.

Phthalimide reacted with phenacyl bromide under microwave irradiation to yield phenacyl isoindolidene-1,3-dione (3b), while 3a reacted with phenylhydrazine to yield the phenylhydrazone 4 that was readily converted into indoylphthalimide 8. Similarly N-benzotriazolylacetone (6a) reacted with phenyl hydrazine to yield the phenylhydrazone 7a that was converted into indoylbenzotriazole 9. Treatment of 8 with hydrazine hydrate afforded a mixture of phthalhydrazide 10 and 3-amino-2-methylindole (11). Reacting enaminone 13 with naphthoquinone (14) afforded the aryl naphthofuran 17. The possibility of the formation of the aldehyde 18 was excluded based on HMQC, which revealed that the carbonyl carbon is not linked to any hydrogen.

Microwave Assisted Dyeing of Polyester Fabrics with Disperse Dyes

Dyeing of polyester fabrics with thienobenzochromene disperse dyes under conventional and microwave heating conditions was studied in order to determine whether microwave heating could be used to enhance the dyeability of polyester fabrics. Fastness properties of the dyed samples were measured. All samples dyed with or without microwave heating displayed excellent washing and perspiration fastness. The biological activities of the synthesized dyes against Gram positive bacteria, Gram negative bacteria, yeast and fungus were also evaluated.

Unexpected Behavior of Enaminones: Interesting New Routes to 1,6-Naphthyridines, 2-Oxopyrrolidines and Pyrano[4,3,2-de][1,6]naphthyridines

Reaction of enaminones 1a–d with 2-aminoprop-1-ene-1,1,3-tricarbonitrile (2) in the presence of AcOH/NH4OAc afforded 7-amino-5-oxo-5,6-dihydro-1,6-naphthyridine-8-carbonitrile derivatives 9a–d. On the other hand, 2-aminopyrano[4,3,2-de][1,6]naphthyridine-3-carbonitriles 20a–c,e were the only obtained products from the reactions of 1a–d with 2 in the presence of AcOH/NaOAc, while 1d afforded [3,5-bis-(4-chloro-benzoyl)-phenyl]-(4-chloro-phenyl)-methanone 21 under the same condition. The reaction of 2 with diethyl acetylenedicarboxylate in the presence of AcOH/NH4OAc afforded (4-cyano-5-dicyanomethylene-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-acetic acid ethyl ester 15B.

Reassignment of the Structures of Products Produced by Reactions of the Product Believed To Be 2-(1-Phenyl-2-Thiocyanatoethylidene)-malononitrile with Electrophiles

The reactivity of the product believed to be 2-(1-phenyl-2-thiocyanato-ethylidene)malononitrile toward a variety of electrophilic and nucleophilic reagents is reported.