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In the present investigation, furo[2,3-d]thiazol-5(2H)-one 5 was obtained from reaction of thiosemicarbazone derivative 2 with diethyl acetylene dicarboxylate. A series of newly synthesized 2-(hydrazinyl)thiazol-4(5H)-one 6, 7 &8 and 2-(4-(substituted)-thiazol-2-yl)hydrazono derivatives 9a, b &10 were synthesized from treatment of thiosemicarbazone derivative 2 with appropriate α-halogenated compounds. Also, a one pot synthesis of thiazole derivatives 13 &15 was achieved from three components reaction of hydrazone derivative 11 with phenyl isothiocyanate and α-halogenated compounds catalyzed by DMF/KOH. 4-(4-Morpholino phenyl) thiazol-2-amino 17 was obtained via the reaction of acetophenone derivative 1 with thiourea in presence of iodine. The reactivity of 2-aminothiazole 17 toward some electrophilic reagents was investigated. The structure of the newly compounds was confirmed on the basis of elemental analysis and spectral data. The antibacterial activity towards two Gram negative (Proteus mirabilis &Serratia marcesens) and two Gram positive (Staphylococcus aureus &Bacillus cereus) bacteria was investigated. The anti-inflammatory activity was also investigated and the inhibition of the carrageenin-induced oedema by these compounds was established., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

2-Thioxo-4-thiazolidinones (3a,b) were achieved by cyclocondensation of isothiocyanatosulfonamides (1a,b) with sulfanylacetic acid at reflux temperature in dioxane in the presence of triethylamine. Compound (3a) was exploited to synthesize the versatile hitherto unknown 2-thioxo-4-thiazolidinones (5-10) via its reaction with some electrophiles. Cyclization of 4,4'-diisothiocyanate diphenylsulfone (11) with sulfanylacetic acid furnished 4,4'-bis(2-thioxo-4-thiazolidinone-3-yl)diphenylsulfone (12) which on treatment with excess 4-methoxybenzaldehyde in refluxing dioxane in the presence of piperidine yielded the bisbenzylidene derivative (13). The novel synthesized compounds were characterized by IR, (1)H NMR and mass spectral studies. All the synthesized compounds were screened in vitro for their antibacterial and antifungal activities.

4-Amino-N-(1-phenyl-1H-pyrazol-5-yl)-benzenesulfonamide (sulfaphenazole) 1 was selected as strategic starting material for the synthesis of some novel acetamide 2, pyrrole 4, pyrrolo[2,3-d]pyrimidine 5, thiocyanate 6, hydrazone 7a,b pyrazole 8, isothiocyanate 9 and thiophene 12 derivatives to evaluate theantitumor activity. Compound 4 was more effective than the reference drug, doxorubicin (CAS 23214-92-8) as positive control.

Several sulfonamides containing pyrroles (2a-c, 6a-d, 8a-d), pyrrolo[2,3-d] pyrimidines (3a-c), acetanilides (11a-c) and tetrahydrobenzothiophenes (13a-c) were synthesized starting from N4-chloroacetylsulfanilamides (1a-d). The structures of synthesized compounds were elucidated by elemental analyses and spectral data. Compounds 2b, 3b, 6b, 8b and 8d exhibited a remarkable antifungal activity compared with the standard fungicide mycostatine.

Pyrazolo[1,5-a]pyrimidines were synthesized via the reaction of ketene dithioacetals and 5-aminopyrazoles. The antibacterial and antifungal activities of some selected compounds are also reported.

Hydrazones 2a-d were prepared from diazotiazation of sulfanilamide or its derivatives followed by coupling with ethyl cyanoacetate. 3-Aminopyrazoles 3a-d were obtained by refluxing of 2a-d with hydrazine hydrate in ethanol. [Bis(-methylthio)methylene]malononitrile (4) was reacted with aminopyrazoles 3a-d in refluxing DMF containing triethylamine to yield the novel pyrazolo[1,5-a]pyrimidines 6a-d. The anilino derivatives 8a-h were obtained by fusion of compounds 6a-d with aromatic amines. When compounds 6a,c,d were subjected to the reaction with hydrazine hydrate, the hydrazino derivatives 9a-c were isolated. Also, the aminopyrazoles 3 were reacted with some electrophiles such as arylidenemalononitriles, ethoxymethylene malononitrile and ethyl ethoxymethylene cyanoacetate to yield the novel substituted pyrazolo[1,5-a]pyrimidines 13, 17 and 19, respectively. Structures of the new compounds were established by their elemental analyses and spectral data. Most of these compounds were also tested in vitro for their antibacterial activity against some gram positive and gram negative bacteria.

The key intermediate octahydroquinazoline (1) was obtained in one pot synthesis by a modification of the Biginelli reaction. Compound 1 was allowed to react with phenacyl bromide and bromomalononitrile to furnish thiazolo[2,3-b]quinazoline 3 and 12, respectively. Interaction of compound 12 with formamide, formic acid and phenyl isothiocyanate yielded the corresponding pyrimidino[4',5':4.5]thiazolo[2,3-b] quinazolines 13, 14 and 17, respectively. The structure of the synthesized compounds were elucidated by elemental analyses and spectroscopic analyses. Some of the prepared compounds were tested for their antifungal activity in comparison with tioconazole as a reference fungicide.

The starting materials thiazolo[2,3-b]quinazolines (5a,b) were obtained in one pot synthesis by treating octahydroquinazoline (2) with chloroacetic acid and aromatic aldehydes. Thiazoloquinazoline (5) was reacted with CH2(CN)2/piperidine and CH2(CN)2/NaOH (CH3OH), to furnish pyrano[2',3':4,5]thiazolo[2,3-b]quinazolines (6a,b) and pyrido[2',3':4,5]thiazolo[2,3-b]quinazoline (7), respectively. Refluxing of 5a with NH2CSNH2/KOH and hydrazines in ethanol furnished the corresponding, [1,3]thiazino[4'5':4,5]thiazolo[2,3-b]quinazoline (10) and pyrazolo[3',4':4,5]thiazolo[2,3-b]quinazolines (11a,b), respectively. Antifungal activity was shown for some of the synthesized compounds.

Naphtho[2,1-b]pyranone (3) was allowed to react with arylmethylenemalononitriles to yield 4-amino-5-oxo-2-aryl-5H-dibenzo[c,f]chromene-3-carbonitriles (4a,b); with ethyl 3,4-dichlorobenzylidene cyanoacetate to furnish dibenzo[c,f]chromene (5) and with elemental sulfur in dioxane containing piperidine to give thieno[3,4-d]naphtho[2,1-b]pyranone (6). Similarly, naphtho[1,2-b]pyranone (7) was reacted with arylmethylenemalononitriles and elemental sulfur to furnish dibenzo[c,h]chromenes (8) and thieno[3,4-d]naphtho[1,2-b]pyranone (10), respectively. Compound 10 underwent cycloaddition with N-arylmaleimides to yield benzo[7,8]chromeno[3,4-f]isoindoles (11a-c). Some of these compounds were screened in vitro for their antimicrobial activities.