Hofmann N‐alkylation of aniline derivatives with alcohols using ferric perchlorate immobilized on SiO₂ as a catalyst through Box–Behnken experimental design

Abstract

Funding information Islamic Azad University-Arak BranchAn efficient method for the N-alkylation of poorly nucleophilic amines using ferric perchlorate immobilized on SiO 2 as a catalyst is described. Fe(ClO 4 ) 3 was prepared from mixing iron(III) hydroxide and perchloric acid and adsorbed on silica gel. The catalyst was characterized using various techniques. The supported ferric perchlorate (Fe(ClO 4 ) 3 /SiO 2 ) revealed high efficiency and selectivity for N-alkylation of aromatic amines with alcohols to provide alkylated amines. Various secondary amines were synthesized from primary amines and alcohols in good to excellent yields, with water as the only by-product. The optimization of the reaction conditions was investigated using the response surface method, and involving the Box-Behnken design matrix. The conditions for optimal reaction yield and time were: amount of catalyst = 0.34 mmol, temperature = 60°C and molar ratio of amine to alcohol = 1.2.The catalyst was recovered and reused for five cycles without a considerable decrease in catalytic activity. The stability of the recycled catalyst was investigated. The proposed method has numerous advantages including procedure simplicity, short reaction times, low cost, good to excellent yields, reusability of the catalyst and mild and environmentally benign conditions.

3‐Amino‐5‐mercapto‐1,2,4‐triazole‐functionalized Fe3O4 magnetic nanocomposite as a green and efficient catalyst for synthesis of bis(indolyl)methane derivatives

“…Following increasing interest in the green and efficient synthesis of heterocyclic compounds, 41–44 in the study presented here a convenient method was introduced for the synthesis of bis(indolyl)methane derivatives in the presence of Fe 3 O 4 /SiO 2 /PTS/AMTA as a novel magnetic catalyst (Scheme 1).…”

QbD approached comparison of reaction mechanism in microwave synthesized gold nanoparticles and their superior catalytic role against hazardous nirto‐dye

“…Presence of significant curvature in responses 3‐D‐Response surface graph (Figure and Figure ) established impact and effects of Quadratic terms i.e., their contribution towards the final responses while overlapping the performance area of individual factors of each response optimized levels of each factor . In ANOVA analysis, impact of significant model terms were expressed as coefficients, positive coefficients terms favouring the response, while negative term inversely related to the response, to generate polynomial mathematical equations which determined Hydrodynamic size, PDI and zeta potential …”

“…While, as the numbers of factors in OFAT approach increased, its starts consuming large amount of resources, time, efforts that's too for estimation of only main effects while, interdependent effects are being totally ignored. Hence, such approach are always contributing bias and poor control over the process . In this perspective, Box–Behnken model offers an alternative solution in terms of providing a design which establish a mathematical model of relationship to enable better control over the process and to enable multi‐objective goal optimization of performances; using the RSM based approach …”

“…Similar to typical chemical reactions, process and performances of microwave synthesis of metallic nanoparticles were depending not only on main factors but also interdependent factor. Hence, controlling the process through adaptation of OFAT approach rather than judicious adaptation of experimental design are not only consuming resources, money, and efforts but also poorly insights of mechanism involved and prediction of final outcomes for multi‐objective goal optimization . So, coupling of Box–Behnken design with different statistical tests provided in‐depth mechanistic information about of significance, impact and role of each factor on final attributes of products as well as help to achieve multi‐objective goal and simulation…”

“…3 3 Second order rotatable design of 17X6 matrix in Box–Behnken design (Matlab® software; Design Expert®) were used to generate mathematical relationship between different process variables; in order to achieve RSM (response surface methodology) based multi‐objective goal optimization …”