thiourea and thiocyanic-acid

Sixteen novel pyrazole acyl thiourea derivatives 6 were synthesized from monomethylhydrazine (phenylhydrazine) and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl chloride intermediates 4 were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in the presence of PEG-400 to afford 5-chloro-3-methyl-1-substituted-1H-pyrazole-4-carbonyl isothiocyanates 5. Subsequent reaction with fluorinated aromatic amines resulted in the formation of the title compounds. The synthesized compound were unequivocally characterized by IR, ¹H-NMR, ¹³C-NMR and elemental analysis and some of the synthesized compounds displayed good antifungal activities against Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica and anti-TMV activity in preliminary antifungal activity tests.

Topics: Acetoacetates; Acylation; Antifungal Agents; Antiviral Agents; Cyclization; Fusarium; Gibberella; Hydrocarbons, Fluorinated; Microbial Sensitivity Tests; Oxidation-Reduction; Phenylhydrazines; Polyethylene Glycols; Pyrazoles; Structure-Activity Relationship; Thiocyanates; Thiourea; Tobacco Mosaic Virus

A novel and sensitive spectrophotometric method for the determination of molybdenum at trace levels in environmental and biological samples is proposed. The method is based on the reaction of Mo (V) with thiocyanate (SCN(-)) and methyltrioctyl ammonium chloride (MTOAC) in acidic medium. The red colored complex of molybdenum is extracted with N-phenylbenzimidoyl thiourea (PBITU) in 1-pentanol for its determination by spectrophotometry. The sensitivity of the present method is higher than other conventional thiocyanate method, due to the use of MTOAC in liquid-liquid extraction. The value of molar absorptivity of the complex with respect to molybdenum is 7.6x10(4)Lmol(-1)cm(-1) at 470nm. The limit of detection of the metal is 5ngmL(-1). The system obeys Beer's law between 20 and 1000ngmL(-1) with slope, intercept and correlation coefficient values of 0.81, 2.5x10(-3) and +0.999, respectively. Most of the metal ions tested did not interfere in the determination of molybdenum. The proposed method has been successfully applied for the determination of the molybdenum in environmental and biological samples.

Topics: Chemistry Techniques, Analytical; Ions; Molybdenum; Oxidation-Reduction; Solvents; Surface-Active Agents; Thiocyanates; Thiourea

A method was purposed for simultaneous determination of ammonium thiocyanate and its isomeride thiourea by dual wavelength multiplication subtractive spectrophotometry. The approach was based on the measurement of the absorbance of both standard solutions and mixture samples at 216 and 236 nm. The concentration of ammonium thiocyanate and thiourea was obtained through the calculation of balancing coefficient and slope. The method was successfully applied to the determination of ammonium thiocyanate and thiourea, which existed in isomerization reaction. A comparison was also made with the dual wavelength method and reversed ion-pair chromamotography, and the dual wavelength multiplication subtractive spectrophotometry offered the advantages of simple, rapid and accurate determination.

Topics: Isomerism; Spectrophotometry, Ultraviolet; Temperature; Thiocyanates; Thiourea

The proposed study of the immunologic reactivity state in chemical plant workers revealed humoral and cellular reactivity changes caused by chemical agents and the workers' immunologic background. It was established that cobalt and manganese salts caused initial immune response.

Topics: Autoantibodies; Chemical Industry; Cobalt; Hemagglutination Tests; Humans; Immunoglobulins; Manganese; Occupational Medicine; Thiocyanates; Thiourea; Ukraine

Topics: Animals; Chemical Industry; Dermatitis, Contact; Dermatitis, Occupational; Guinea Pigs; Humans; Immunity; Rats; Thiocyanates; Thiourea

Topics: Air Pollutants, Occupational; Animals; Maximum Allowable Concentration; Rabbits; Rats; Thiocyanates; Thiourea; USSR