The Reduction of Nitrobenzene by Hydrosulphide Ion in Aqueous Media

Abstract

Uepc~rt~~le?lt of Cliet~tzstry, G1~loers~t31 of illbefta, Edlno~tto?~, iliberte Received June 11, 19G'S i2BSrI'R.-1 CTT h e retluctior~ of nitrobenzenc by sodium hydrosulphide and sodiiim hpdrotlisulphide in aqueoils media a t 50' has bee11 examined. Goltlschmiclt's report oE lirst-order dependence Llporl both ~~itrobelizenc arid hyclrosrilphide is corroboratetl. 'I'he action oE hydrosulphide on nitrobcrrzel~e procluces phenylhydrosyla~nilli~~e, which is reduced by hydrosulphitie m~~c l i tilore slowly than is l~itrobenzene. rls reaction progresses, nitrobenzene reduction protluces yello\v liydroclisulpl~icle, which is responsible for the observecl atrtocatalytic eiEect. Flyclrodisulphitlc reduces phenylliydroxylarnine more rapidly than it tloes the original nitroberizene, and lience as reaction time is extended, p l~e n~~l h y d r o s y l a n~i l~e disappears niore rapidly than does tiitrobenzei~e, yielding only aniline and some ~inreactetl nitrobenzene to\vards the eilcl of the reaction. Hydrosrilpliide retluction of plier~ylhydroxyla~i~ii~e t o aniline produces thiosulphate but apparently no hydrodis~~lphidc. Hyclrodis~ilphide reduction of the phenylhydrosylanline leads only to conversion oE the yello\v hydrodisulphidc to a colorless species, apparelitiy thiosiilphate. On the other liancl hytlrosulphide or hyclrodisulphide reduction of nitrobenzene is accolnpanied by thiosulphate formation ancl sorne increase in hydrodisulpiiicle. ri comparison of the rate constants sho~vs that ~~i i d e r the co~iclitions of the reaction, hyclrotlis~llphide ion reduces nitrobenzene about se\.en times more rapidly than does hydrosulphicle ion while phe~~ylhydrosylar~ii~ie is reti~lced tmo to three timcs more rapidly by hydroclisulphide than is nitrobenzene.The use of sodium hydrosulphide for the selective I-eduction of nitro groups in the aromatic nucleus is lvell ltnown. This reagent has been prepared for this purpose by treatnlent of sodium monosulphide with 1 equivalent of sodiu~n bicarbonate (I), or, in the for111 of lnore acidic systems, by bubbling hydrogen sulphide through a solutioll of the reducible substance contailling a catalytic a~n o u n t of ammo~lia (2). The addition of excess a~lllnoniu~n salts to a solutio~l of hydrosulphide has also been elnployed to produce hydrosulphide under co~lditio~ls designed t o maintain a pI-I of 7.5 to 8.0 (3).The only reported kinetic study of the hydrosulphide reduction is that of Goldschmidt and Larsen (A), who investigated the reduction in aqueous solution a t 25' C of various nitro compounds by sodiunl I~ydrosulpl~ide saturated with hydrogen sulphide. Tlle conditions of their reaction resulted in conversion of the nitrobenzene to the corresponding N-pl~enylhydroxylamine along with co~nplete precipitation of the sulphur formed according to equation (a). The rate of reductiorl was found to be first order in nitrobenzene, first order in hydrosulpl~ide ion, and illdepellde~lt of hydl-ogen sulphide concentration.In a previous paper ( 5 ) we have shown that the S,= species reduces ...

Potential for Abiotic Reduction of Pesticides in Prairie Pothole Porewaters

“…Notably, reactions in native porewaters were faster than those in filter-sterilized porewaters ( k obs,native / k obs,filtered ≈ 1.50; see Table ), suggesting that the filtration process might have removed certain reactive entities in native porewaters that would otherwise react with dinitroanilines (see further discussion below). In sulfide redox buffers, the reactions of dinitroanilines with HS – and S n 2– were determined to be first order in [HS – ] and ∑[S n 2– ], respectively (see Figures S2 and S3, Supporting Information), which agrees with previous reports on the reaction order of monosubstituted NACs with HS – and S 2 2– . − Second-order rate constants for reactions of dinitroanilines with HS – ( k HS – ) were computed by dividing k obs measured in the hydrogen sulfide buffer by [HS – ], while second-order rate constants for reactions of dinitroanilines with S n 2– ( k S n 2– ) were estimated by dividing k obs measured in the polysulfide buffer by ∑[S n 2– ], after first correcting k obs to account for the contribution from reaction with HS – . For all dinitroanilines, a greater reactivity toward S n 2– than HS – was found, suggesting that S n 2– species are indeed much more reactive reductants ( k S n 2– / k HS – = 16–22; see Table ).…”

“…This seems to contrast with the slow direct reduction of monosubstituted NACs by HS − shown in earlier studies. 32,33,49 A plausible explanation for the significant direct reduction by HS − and S n 2− is that the two nitro groups on dinitroanilines may exhibit higher electron affinities, making them susceptible to faster reduction. In fact, previous work has shown that the direct reduction of polysubstituted NACs by HS − can account for up to 35% of their overall reactivities in the H 2 S−juglone system.…”

“…The transfer of the first electron from HS – to NACs is generally considered to be a highly endergonic process, and the direct reduction of some monosubstituted NACs by HS – has been documented as a slow process with respect to their facile transformations sometimes observed in anoxic environments. , The addition of NOM or its structural analogues containing redox-labile functionality often can accelerate rates of NAC reduction by orders of magnitude in the hydrogen sulfide system. ,, The role of NOM has most commonly been ascribed to its ability to serve as an effective electron transfer mediator that shuttles electrons between HS – (bulk electron donors) and NACs (electron acceptors). ,, Such NOM constituents often contain quinone or its sulfur derivatives (e.g., mercaptoquinone) that result from addition reactions with hydrogen sulfide. − In contrast to HS – , polysulfide ions are kinetically more reactive reductants toward NACs even though they are more oxidized. − Nonetheless, the direct reduction of NACs by S n 2– has not been fully explored under environmentally relevant conditions.…”

Iron Sulfide Catalyzed Redox/Condensation Cascade Reaction between 2-Amino/Hydroxy Nitrobenzenes and Activated Methyl Groups: A Straightforward Atom Economical Approach to 2-Hetaryl-benzimidazoles and -benzoxazoles

“…However, 3-picoline 2h failed to react with 1a (entry 8, Table ) and both starting materials were recovered unchanged. This result is in agreement with earlier observed reactivities of the methyl groups of picolines in elemental sulfur-mediated oxidation . This difference in reactivity was demonstrated clearly when 3,4-lutidine 2g reacted with o -nitroaniline 1a and afforded only one product, 3ag …”

Reduction of Nitro Group by Sulfide and Its Applications in Amine Synthesis

“…S O -(Eq. 16) [27] ; 或者单质硫与 硫化物反应产生多硫化物(Eq. 17 子继续参与反应, 另一部分会发生聚合形成聚硫(S 2 ～ S 5 ) [28] ; 当 3≤n≤6 时, 就会发生首尾相连脱去一分子硫…”