Synthesis and antitumor activity evaluation of some schiff bases derived from 2‐aminothiazole derivatives

A novel series of thiazolyl Schiff bases have been designed and synthesized. These new compounds were obtained by the reactions of 4‐phenyl‐5‐(1H‐1,2,4‐triazol‐1‐yl) thiazol‐2‐amine and substituted aromatic aldehydes and were characterized on the basis of ¹H NMR and elemental analysis. The newly synthesized compounds were screened for their antitumor activity against human cancer cell lines, namely HL‐60 (leukemia), BGC‐823 (stomach), and HEP‐2 (larynx cancer). © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:55–59, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20256     

Synthesis and analgetic activity of sulfur-containing morphinans and related compounds

3-Acylthiomorphinans, 3-carbamoylthio-3-deoxydihydromorphine and 3-benzoylthio-9-aza-17-carbamorphinan were synthesized by Newman-Kwart rearrangement of the corresponding O-thiocarbamates. The analgetic activities were lower than that of pentazocine, and the opioid receptor binding affinities were very weak. These acylthiomorphinans showed low antinociceptive activity compared with corresponding sulfur-containing benzomorphans. 3-Carbamoylthio-deoxydihydromorphine had no significant analgetic activity.     

Electrospray tandem mass spectrometric investigations of morphinans

In this study positive ESI tandem mass spectra of the [M + H]+ ions of morphinan alkaloids obtained using an ion trap MS were compared with those from a triple quadrupole MS. This allows to assess the differences of the tandem-in-time versus the tandem-in-space principle, often hampering the development of ESI MS/MS libraries. Fragmentation pathways and possible fragment ion structures were discussed. In order to obtain elemental composition, accurate mass measurements were performed. According to the MS/MS fragmentation pathway, the investigated compounds can be grouped into 4 subsets: (1) morphine and codeine, (2) morphinone, codeinone, and neopinone, (3) thebaine and oripavine, (4) salutaridine and salutaridinol. Salutaridinol-7-O-acetate shows a different fragmentation behavior because of the favored loss of acetic acid. Although most fragment ions occur in both ion trap and triple quad tandem mass spectra, some are exclusively seen in either type. For triple quad, quadrupole time-of-flight and FT-ICR MS/MS, the base peak of morphine results from an ion at m/z 165 that contains neither nitrogen nor oxygen. This ion is not found in ion trap MS/MS, but in subsequential MS3 and MS4.     

One-pot N-dealkylation and acid-catalyzed rearrangement of morphinans into aporphines

The one-pot N-demethylation and acid-catalyzed rearrangement of morphinan-N-oxides offers a new, shorter and more efficient route to neuropharmacologically important N-substituted aporphines. An improved procedure is described for the preparation of the starting alkaloid N-oxides using Na₂WO₄ as catalyst. The transetherification during the rearrangement of codeinone into 2-O-alkyl-norapocodeines is documented.     

An efficient protocol for solid phase aminothiazole synthesis

An efficient synthesis of 2,4-diamino-5-ketothiazoles under solid phase conditions has been achieved by the reaction of polymer supported amidinothioureas with α-haloketones. This novel synthetic approach involving traceless cleavage from the support is suited for automation, and allows solid phase combinatorial synthesis of 2,4-diamino-5-ketothiazoles in good yields and purities.     

Synthesis of resorcinol derived spironitronates

Syntheses of several unique spironitronates are reported. The key transformation involves the first known example of an ipso oxidative cyclization of nitro functionality. Oxidation proceeds from both o- and p-phenols. Reductions of these compounds provide novel spiroisoxazoline derivatives.     

Synthesis of oxazolidinedione derived bicalutamide analogs

The synthesis of chiral oxazolidinedione derived bicalutamide analogs has been discussed.     

Synthesis of dihydrooxazole analogues derived from linezolid

Starting from (S)-serine, the linezolid analogue 3 with dihydrooxazole partial structure was synthesized and pharmacologically investigated. With the help of MEP comparisons structural requirements for antibacterial activity were evaluated.     

Synthesis of novel iodo derived bicalutamide analogs

A series of optically active nonsteroidal selective androgen receptor modulators with structures analogous to bicalutamide was prepared by replacing the trifluoromethyl group with iodine and the sulfonyl linker by oxygen.     

Synthesis of a new catechin-pyrylium derived pigment

A new catechin-pyrylium derived pigment compound was synthesised from the reaction of catechin with sinapaldehyde in acidic conditions and its structure has been characterised by UV-vis, MS and NMR spectroscopy. Similar compounds could be expected to be formed in wines and contribute to changes in colour and astringency during ageing.     

Antibakterielle wirkstoffe. VIII . Die aminomethinylierung in der reihe der aminothiazole

The three-component reaction comprising the interaction of 2-amino-4-antipyrinyl-5-ethylthiazole (1) with s-triazine (2) and pyrrolidine leads to 4-anitpyrinyl-5-ethyl-2-[(4-pyrrolidinyl)methyleneamino]thiazole (5). Structure 5 is supported by ¹H- and ¹³C-NMR spectroscopy.     

Synthesis of condensed azaheterocycles derived from 2,3-dichloropyrazine

A study was carried out on the reaction of 2,3-dichloropyrazine with compounds containing an activated methylene group. The reaction course and structure of the final products are a function of the nucleophile.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 107–111, January, 1992.     

Synthesis and characterization of bismaleimides derived from polyurethanes

A series of novel bismaleimides (BMIs) were prepared from maleic anhydride and polyurethane prepolymers based on MDI (4,4′-diphenylmethane diisocyanate) and polyether and polyester diols with various chain lengths. All the BMIs were characterized by IR, ¹H-NMR, and elemental analysis. DSC studies indicated that the thermal polymerization of the BMIs could be carried out in the temperature range of 102–245°C, and that curing behavior was significantly affected by the molecular weight of the BMIs. The crosslinked BMI elastomers showed good mechanical properties and much better thermal stability than that of the traditional polyurethane elastomers. The glass transition temperatures, mechanical, and dynamic mechanical properties were dependent on the types of polyols used and the resultant crosslink densities due to various chain lengths of the BMIs. © 1994 John Wiley & Sons, Inc.