Ultrasonically Assisted Regioselective Nitration of Aromatic Compounds in Presence of Certain Group V and VI Metal Salts

Abstract

Ultrasonically assisted nitration reactions (USANR) with anilides, moderately activated and non-activated aromatic compounds underwent smoothly and afforded good yields of products with high regio selectivity. Observed longer reaction times (6 - 8 hrs.) in metal catalyzed reactions reduced to (1 - 2 hrs.) under sonication. When ortho position is blocked para derivatives are obtained, and ortho nitro products are obtained when para position is blocked. In case of USANR of aromatic carbonyl and related compounds the effect of sonication is much more effective. The reactions could be completed only in few minutes

Fe3O4 Nanoparticles Synthesized from Waste Iron Dust for Sunlight-Boosted Photodegradation of Nitrophenols and Their Mixtures

“…Figure comprises photographic images of an aqueous solution of N-PhOHs and their mixtures along with the 1 H NMR spectra before and after the degradation and their chemical structures with the corresponding labeled protons. The 1 H NMR spectra of PNP (Figure a, green line) showed two peaks for two different benzylic protons at ∼6.9 (d, 2 H a ) and ∼8.1 ppm (d, 2 H b ); in the case of DNP, mainly three different benzylic hydrogens showed chemical shifts at ∼7.4 (d, H c ), ∼8.5 (dd, H d ), and ∼8.8 ppm (d, H e ) as shown in Figure b, green line. Similarly, in the proton 1 H NMR spectra of TNP (Figure c, green line), two peaks appeared at ∼8.5 ppm (s, 2 H g ) corresponding to benzylic hydrogen and ∼5.0 ppm (s, H f ) corresponding to phenolic hydrogen.…”

“…The magnetization curves represent the decrease in coercive force (H c ) and permanent magnetization (M r ) from ∼397.58 to ∼3.85 O e and from ∼0.24 to ∼0.14 emu g −1 , respectively, for IOD and Fe 3 O 4 -NPs. This clearly states the insertion of an additional magnetic ferrite phase after chemical reduction via Na 2 S. Additionally, the value of magnetic saturation (M s ) was greatly increased from ∼1.31 to ∼36.68 emu g −1 for IOD and Fe 3 O 4 -NPs, 47 respectively (as shown in the inset of Figure 1b), which supports the drastic change in magnetic properties before (antiferromagnetic) 48 and after (close to superparamagnetic) 49 by in situ generation of the Fe(II) phase during the process of chemical reduction.…”

“…The 1 H NMR spectra of PNP (Figure 5a, green line) showed two peaks for two different benzylic protons 47 5b, green line. Similarly, in the proton 1 H NMR spectra of TNP (Figure 5c, green line), two peaks appeared at ∼8.5 ppm (s, 2H g ) corresponding to benzylic hydrogen and ∼5.0 ppm (s, H f ) corresponding to phenolic hydrogen.…”

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“…They have recently been identified as possible promoters for a variety of organic transformations, including those involved in the synthesis of coumarinderived molecules [63]. Throughout this respect, it has been recorded that this sort of promoter has been used in a variety of reactions that are managed and executed under ultrasonic radiation, including the halogenation addition reactions [64] and the Heck reaction [65]. For example, the ultrasound facilitated condensation, as illustrated in Scheme 25, between the derivatives β-ketoester and phenol utilizing BiC13 as a reaction promoter [39,63].…”