P-Methoxyaniline

General Conditions for each step and selectivity of m-substituted anilines As previously mentioned, Hauser and Reynolds reported on factors governing the first step of the Conrad-Limpach reaction but they tvere by no means exhaustive. Other than the conditions reported above for the first step, HClAleOH, CHCI3 or CHCI2 (neat or with acid catalyst), PhMe or PhH with removal of water with or without acid catalyst, or EtOH/AcOH/CaS04 were reported to provide the desired enamino-ester from an aryl amine and 3-keto-ester. Hauser and Reynolds also noted that o-nitroaniline and o-nitro-p-methoxyaniline failed to form the desired enamino-ester under conditions which they reported. 

An excellent route to cyclohexylamines is by hydrogenation of the corresponding aniline over rhodium or ruthenium (17,18,19 2 36,63,64). Rhodium has proved especially useful in saturation of alkoxyanilines with minimal hydrogenolysis of the alkoxy function (45), The extent of hydrogenol ysis occurring in saturation of alkoxyanilines depends also on the solvent. Hydrogenolysis of p-methoxyaniline over Ru(OH)2 fell with alcohol solvent in the order methanol (35%) > ethanol (30%) > propanol (26%) > butanol (22%) > isopropanol (16%) > r-butanol (8%) (43). 

According to Trautman (16), PNA was converted almost exclusively to p-nitrophenol in the mouse with 24 hours, nearly all of which was excreted in the urine as glucuronide, sulfate, glucoside, and unextractable products the mouse tissue retained only about 1% of the original dose. By comparison, the sea urchin metabolized PNA slowly p-nitrophenol and its conjugates accounted for only about 6% of the metabolites and most of the remainder (90%) was p-anisidine (p-methoxyaniline) and its N-acetyl derivative. 

Synonyms AI3-02392 4-Aminoanisole p-Aminoanisole l-Amino-4-methoxybenzene 4-Aminomethoxybenzene jo-Aminomethoxybenzene jo-Aminomethylphenyl ether 4-Anisidine p-Anisylamine CCRIS 917 p Dianisidine 4-Methoxy-l-aminobenzene 4-Methoxyaniline p Methoxyaniline 4-Methoxybenzenamine p-Methoxybenzenamine 4-Methoxyphenylamine p-Methoxyphenylamine NSC 7921 UN 2431. 

Methoxyaniline, see o-Anisidine p-Methoxyaniline, see p-Anisidine 2-Methoxybenzenamine, see o-Anisidine 4-Methoxybenzenamine, see p-Anisidine p-Methoxybenzenamine, see p-Anisidine Methoxycarbonylethene, see Methyl acrylate Methoxycarbonylethylene, see Methyl acrylate 2-Methoxycarbonyl-l-methylvinyl dimethyl phosphate, see... 

Akiyama applied Im in the inverse-demand aza-Diels-Alder reaction of various acyclic and cyclic vinyl ethers with N-aryl imines derived from o-hydroxyaniline to provide ophcally active tetrahydroquinoline derivatives (Scheme 5.16) [29]. Since aldimines derived from p-methoxyaniline gave no cycloaddition product, a nine-membered cyclic TS (akin to that proposed for the author s Mannich reachon) was invoked to rationalize the high levels of enantio-control. 

Aryl alkyl amines gave hydroxylamine 0-arylsulfonates when reacted with arylsul-fonyl peroxide. The products were later decomposed to azomethine and further hydrolysis results in the corresponding amine with one less carbon atom. Thus when p-methoxy-benzylamine was treated with p-nitrophenylsulfonyl peroxide at —78 °C in ethyl acetate, p-methoxybenzaldehyde and p-methoxyaniline were obtained . Cyclic amines with p-nitrophenylsulfonyl peroxide were converted to the Al-(p-nitrophenylsulfonyloxy)amine derivatives, which further rearranged to ring-expanded cyclic imines in good yields (equation 9 f. ... 

The activity of some catalytic systems has been studied. For example, Deng has shown that the synthesis of symmetric ureas from aliphatic or aromatic primary amines and C02 can be promoted by catalytic amounts of CsOH in several ILs [128a], Under the working conditions employed (443 K, 6 MPa C02 pressure), the best activity was shown by the system CsOH/BMImCl, whilst the urea yields (up to 98% within 4h, for N,N -dicyclohexylurea) were shown to depend on the amine used. Aromatic amines, such as aniline or p-methoxyaniline, were less reactive than their aliphatic counterparts and afforded the relevant urea in modest yield (27 and 33%, respectively), but only after long reaction times (36 h). In a later study, the same group showed that the synthesis of disubstituted symmetric ureas (RNH)2CO (R = alkyl) from amines and C02 could be promoted also by catalytic... 

Figure 5.61 Schematic representation of a [Ru(bpy)3]2+/a-ZrP viologen structure on silica, plus the sequence of fast (1,2) and slow (3) electron transfer steps that follow photoexcitation of the photoactive ruthenium-containing polymer MDESA, p-methoxyaniline diethylsulfonate. Reprinted from Coord. Chem. Rev., 185-186, D. M. Kaschak, S. A. Johnson, C. C. Waraksa, J. Pogue and T. E. Mallouk, Artificial photosynthesis in lamellar assemblies of metal poly(pyridyl) complexes and metalloporphyrins, 403-416, Copyright (1999), with permission from Elsevier Science...

An important application of oxidation of a C-H bond adjacent to a nitrogen atom is the selective oxidation of amides. This reaction proceeds in the presence of ferf-BuOOH as the oxidant and Ru(II) salts. Thus in the example of Eq. (36), the a-tert-butylperoxy amide of the isoquinoline was obtained, which is an important synthetic intermediate for natural products [138]. This product can be conveniently reacted with a nucleophile in the presence of a Lewis add. Direct trapping of the iminium ion complex by a nudeophile was achieved in the presence of trimethylsilyl cyanide, giving a-cyanated amines as shown in Eq. (37) [45]. This ruthenium/peracid oxidation reaction provides an alternative to the Strecker reaction for the synthesis of a-amino acid derivatives since they involve the same a-cyano amine intermediates. In this way N-methyl-N-(p-methoxyphenyl) glycine could be prepared from N,N-dimethyl-p-methoxyaniline in 82% yield. 

A change in rate and/or mode of propagation can be brought about by orientation of monomer molecules in the liquid crystalline state. For vinylo-leate in the smectic phase, a higher polymerization rate than in the isotropic phase was observed by Amerik and Krentsel [28]. A significant reduction in the polymerization rate of a relatively complex monomer [N-(p-acryloyl-oxybenzylidene)-p-methoxyaniline] in the nematic state was described by Perplies et al. [29], On the other hand, Paleos and Labes observed no change in the polymerization kinetics of a monomer, also of Schiff base character... 

Oxidative demethylation A new approach to indoloquinones such as 5 involves Michael addition of ethyl acetoacetate to the quinone monoimide 1 to give 2, which is dehydrated to the indole 3 in 73% overall yield. The latent quinone ring is then modified to give the p-methoxyaniline 4. The final step involves the oxidative demethylation reaction of Rapoport (4, 431-432) to give an intermediate quinone imine, which is hydrolyzed to 5. 

Many papers have been published on the reactions that occur generally with low to moderate yields of alkali amides with aryl halides in liquid ammonia8. For example, treatment of p-bromoanisole with KNH2 in liquid ammonia generated a 1 1 ratio of m- and p-methoxyaniline, in a 31% yield17. Perchlorobenzene has been shown to react vigorously with amide ion in liquid ammonia. The major product obtained is a triaminobenzene together with chloride ion. 

The usual procedures for use of PPA in the Schmidt reaction call for a temperature in the range 60-100° or even higher. Stockel and HalP report that improved yields can be obtained at room temperature (excess sodium azide is used). However, the yield depends upon the substituents present. Thus p-nitrobenzoic acid gives p-nitroaniline in only 50% yield, whereas p-methoxyaniline is obtained from p-methoxybenzoic acid in 80% yield. 

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