Response surface methodology (RSM)
was employed to model and optimize
an improved Zinin reduction of a nitroarene, p-nitroacetophenone
(p-NAP), by hydrogen sulfide (H2S) under
biliquid phase transfer catalysis. A novel Zinin reagent, H2S laden aqueous N-methyldiethanolamine (MDEA) solution,
was prepared and used for this purpose. A quadratic regression model
was tested with a multivariate experimental design based on the relationship
between p-NAP conversion (response) and four independent
variablestemperature, catalyst concentration, p-NAP–sulfide mole ratio, and MDEA concentration. The optimum
values of the independent variables were found as temperature 339.45
K, catalyst concentration of 0.082 kmol/m3, p-NAP/sulfide mole ratio of 0.452, MDEA concentration of 2.20 kmol/m3, and maximum p-NAP conversion of 96.31%
has been attained. The analysis of variance (ANOVA) has been used
to evaluate the goodness of the fit of the model, and the desirability
function has been used to find the value of the optimized parameters
to maximize the p-NAP conversion.