Amines nitro ketones

The N,]S -dialkyl-/)-PDAs are manufactured by reductively alkylating -PDA with ketones. Alternatively, these compounds can be prepared from the ketone and -lutroaruline with catalytic hydrogenation. The /V-alkyl-/V-aryl- -PDAs are made by reductively alkylating -nitro-, -nitroso-, or /)-aminodipheny1 amine with ketones. The AijAT-dialkyl- PDAs are made by condensing various anilines with hydroquinone in the presence of an acid catalyst (see Amines-aromatic,phenylenediamines). 

The reduction of y-nitroketone acetals as in Eq. 6.50 v/ith ammonium formate in the presence of Pd/C gives the correspondmg amines in good yields. However, the reduction ofy-nitro ketones are reduced to cyclic nitrones fEq. 6.51. This reduction is far superior to the classical method using Zn/T4HlCl due to improved yield and simple workup. 

The addition-elimination reaction of hetero-atom-substituted nitroalkenes provides functionalized derivatives of unsaturated nitro compounds.26 Nitroenamines are generally prepared from a-nitro ketones and amines (see Chapter 5 regarding acylation of nitro compounds).26... 

Carboxylic acid, aldehyde, ketone, ether, alcohol, ester, ester-R (the chain attached to the oxygen atom being a generic substituent), anhydride, acetal, amide, epoxide, acid halyde, primary amine, primary imine, cyano, secondary amine, secondary imine, tertiary amine, nitro derivative, metal-1, metal-2, carbene, halo derivative. 

Class 3 Liqnids composed of molecules containing donor atoms, but no active hydrogen atoms, e.g., ethers, ketones, aldehydes, esters, tertiary amines, nitro componnds withont a-hydrogen, phosphoryl-gronp containing solvents, etc. (see Table 4.3). They are generally called dipolar aprotic snbstances. 

Saturated hydrocarbons Olefinic hydrocarbons Aromatic hydrocarbons Halocarbons Mercaptans Sulfides CS2 Ethers Ketones Aldehydes Esters Tertiary amines Nitro compounds (without a-H atoms) Nitriles (without a-atoms)... 

Reductive amination amides and lactams.1 The a-nitro ketone 1, prepared as shown, on reduction with NaBH4 in the presence of ammonia gas is converted into the amide 2 in 30% yield. 

Metabolism is almost always an oxidative process. Reductive metabolism is much more limited. Functional groups that are reduced are, naturally, in a higher oxidation state. The more common examples include nitro groups, which are reduced to amines, and ketones, which reduce to alcohols. Chloramphenicol (8.28), an antibiotic that has fallen out of favor because of serious side effects, contains a nitro group that is reduced to the corresponding amine (8.29) (Scheme 8.9).7 Warfarin (Coumadin, 8.30), an anticlotting agent, is at least partially metabolized by reduction of its ketone to an alcohol. 

Nitroalkenes (see 30) are easily made from nitro-alkanes and aldehydes and take part as dieno-philes in Diels-Alder reactions (chapter 17). The products can, as usual, be converted into amines or ketones. The stimulant fencamfamin 39 disconnects to the obvious Diels-Alder adduct 41 from cyelopentadiene 42 and the nitro-alkene 43. 

Nitroalkane anions are very stable and hence excellent at conjugate addition (chapter 22). Quite weak bases such as amines are enough to give the anion of 44 and hence the nitro-ketones 45. Reduction gives the amino-ketones 46 that cyclise to give imines, reduced under the reaction conditions to pyrrolidines 47. 

The popularity of the Nef reaction is due in part to the ready availability of nitro compounds. Primary and secondary halides react with sodium nitrite in dimeAyl sulfoxide (DMSO) or dimethylform-amide (DMF) to give useful yields of nitro compounds. Primary amines can be oxidized to nitro compounds with potassium permanganate, m-chloroperbenzoic acitP or ozone. Chlorination of oximes with hypochlorous acid and reduction with magnesium, zinc or hydrogen/lpalladium gives secondary nitro compounds. Stabilized carbanions can be nitrated by treauitent with a nitrate ester, and enol acetates are nitrated by acetyl nitrate to give nitro ketones. ... 

Disposal methods for some of the more common classes of organic compounds may be found in Chemical Safety Matters (hydrocarbons halogenated hydrocarbons alcohols and phenols ethers, thiols, and organosnlfnr componnds carboxylic acids and derivatives aldehydes ketones amines nitro and nitroso componnds and peroxides). 

Nitro compounds are versatile synthetic intermediates which have found widespread utility in industrial applications. Aromatic nitro compounds are the usual starting materials for commercial applications, but aliphatic compounds exhibit a greater diversity of chemical behavior under reducing conditions. " Nitroso compounds, hydroxylamines, oximes, amines, nitrones, ketones and silyl nitronates are frequently encountered during the reduction of nitro compounds. Several specialized reviews have appeared which highlight the versatility of the nitro group in organic chemistry. ... 

An extension of this cleavage process involves the reaction of a-nitro ketones (0=C-CHRN02) with a primary amine, neat, to give the corresponding amide (0=C-NHR ). ... 

In contrast to ammonia, primary, secondary, and tertiary amines can add to aldehydes and ketones to give different kinds of products. Primary amines give imi-nes and secondary amines gives enamines (10-69). This section will focus on imines. Reduction of co-azido ketones leads to the amino-ketones, which cyclizes to form a 2-substituted pyrroline. Reduction of nitro-ketones in the presence... 

Many olefin functional groups survive hydrosilylation. Thus, olefins bearing oxirane, acetal, ester, nitrile, amine, amide, nitro, ketone, carbamate, ether, isocyanate, phosphate, phophonic dichloride, dialkoxyborane, sulfide, sulfone, or carborane groups are readily hydrosilylated without affecting the functional groups, as shown in Table 1. 

Separation of mixtures of saturated hydrocarbons has been effected on silica gel or charcoal. Alcohols, phenols, aldehydes and ketones, acids, esters and lactones, amines, nitro compounds, azo compounds, halogen and sulphur compounds, sugars and glycosides, alkaloids, natural dyes, vitamins, harmones, antibiotics etc. have been separated under appropriate conditions. 

Although these conditions are quite general for a wide variety of aryl bromides, the use of a strong base (NaOr-Bu) can be incompatible with base sensitive, enolizable, substituents (R1). To address this limitation, Buchwald was able to replace NaOf-Bu with CS2CO3. This allowed for aryl bromides substituted with an ester, nitrile, nitro, ketone, or aldehyde to couple cleanly with primary amines and cyclic secondary amines. 

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