The nitration process of salicylic acid for the production of the important intermediate 5-nitrosalicylic acid is studied from thermokinetic and safety points of view. Investigations carried out by considering, as process deviations, the loss of the thermal control point out the possibility of runaway phenomena due to the occurrence of polynitration reactions. Isothermal experiments are carried...

A derivative spectrophotometric method was developed to determine NO3(-)-N in plant tissues. The method is based on measurement of the first-derivative spectrum of nitrosalicylic acid in basic solution. The nitrosalicylic acid was obtained by reaction of samples with salicylic acid in concentrated sulfuric acid and was used by Cataldo et al. in nonderivative spectrophotometry. The main strength...

5-aminosalicylic acid (5-asa) is currently prepared by electrochemical reduction of 5-nitrosalicylic acid (5-nsa) in acidic media. in this work, electrolytic reduction of 5-nsa in alkaline media is presented. reactionconditions and parameters such as anode and cathode electrodes, electrolyte type, reaction time, temperature,current, and the ph for isolation of product are investigated. the yiel...

5-Aminosalicylic acid (5-ASA) is currently prepared by electrochemical reduction of 5-nitrosalicylic acid (5-NSA) in acidic media. In this work, electrolytic reduction of 5-NSA in alkaline media is presented. Reactionconditions and parameters such as anode and cathode electrodes, electrolyte type, reaction time, temperature,current, and the pH for isolation of product are investigated. The yiel...

Complexes of yttrium(III) formed with 5-sulphosalicylic acid, 5-SSA (H3L), and 5-nitrosalicylic acid, 5-NSA (H2L), were investigated in 0.1 mol.dm −3 sodium perchlorate ionic medium at 25.0 ± 0.1 ◦C potentiometrically for various molar ratios of Y(III) to these salicylic acid, SA (H2L), derivatives. Y(III) forms YL and YL3− 2 type complexes with 5-SSA that have rather high stabilities (log β1= ...

the protonation constant values of salicylic and 5-nitrosalicylic acid werestudied by a combinationof spectrophotometric and potentiometric methods at 25 °c in wide range of ionic strength. the ionicstrength of solutions was kept constant by sodium perchlorate as background electrolyte at 0.10 to 3.0 moldm-3. potentiometer was calibrated according to gran method at each of ionic strength. the p...

The complexes of chromium(III) ion formed by salicylic acid, SA(H(2)L), and its derivatives (H(2)L): 5-nitrosalicylic acid (5-NSA), 5-sulphosalicylic acid (5-SSA) were investigated by means of potentiometry and spectroscopy, at 25 degrees C and in ionic strength of 0.1 M KNO(3) and 0.1 M KCl, respectively. Over the acidic pH range, the coordination of Cr(III) ion to SA and its derivatives in 1 ...