4-Nitrobenzoic acid, reduction

High dietary carbohydrate levels in the rat tend to have much the same effect as low dietary protein, decreasing such activities as aminopyrine A -demelhylase, pentobarbital hydroxy lation, and / -nitrobenzoic acid reduction along with a concomitant decrease in the enzymes of the cytochrome P450 monooxygenase system. Because rats tend to regulate total caloric intake, this may actually reflect low-protein intake. 

Another route is starting with m-nitrobenzoic acid, reduction and diazotization as in case of m-anisic aldehyde... 

It should be noted that only representative substances are indicated in the above list. Substituted derivatives of the compounds in most classes may be encountered, e.g., nitrobenzoic acid in the aromatic carboxylic acids (p. 347). This acid will contain CH(0)N, but the salient properties are still those of a carboxylic acid, CH(0), Section 14, although the properties of an aromatic nitro-compound (e.g.y reduction to an amino-compound) will also be evident. 

Mesalamine. Rowasa, Asacol, and Pentasa are trade names for mesalamine [89-57-6] (5-ASA, 5-amino-2-hydroxybenzoic acid). It is a white to pinkish crystalline substance that is slightly soluble in cold water and alcohol, more soluble in hot water, and soluble in hydrochloric acid. It may be prepared by the reduction of y -nitrobenzoic acid with zinc dust and HCl. 

Aminofurans cannot be prepared by reduction of 2-nitrofurans or by hydrolysis of 2-acetamidofurans. The latter are prepared by the reduction of 2-nitrofurans in the presence of acetic anhydride. Benzofuranone (161) and not 2-aminobenzofuran is obtained from tin and hydrochloric acid reduction of 2-nitrobenzo[h]furan (160). 

We have noted above that benzocrowns may be nitrated quite readily. This approach was used in the formation of a photoresponsive bis-crown (see Sect. 3.8) wherein the nitrobenzo crowns reductively dimerize to the corresponding azobenzene. Kikukawa, Nagira and Matsuda have utilized 4-nitrobenzo-15-crown-5 in a somewhat different way during the synthesis of 4 -vinylbenzo-l 5-crown-5Nitration is effected using nitric acid in a mbcture of chloroform and acetic acid. 

Reduction of substituted 2-nitrobenzoic acid to 2-nitrobenzyl alcohol Sterling Organics Amery et al. (1993)... 

Risocaine (28) manages to retain local anesthetic activity even without having a "basic ester" moiety.10 Its synthesis follows classic lines involving esterification of p-nitrobenzoic acid with thionyl chloride followed by reaction with propanol, and then catalytic reduction to complete the scheme. 

Iridium-catalyzed transfer hydrogenation of aldehyde 73 in the presence of 1,1-dimethylallene promotes tert-prenylation [64] to form the secondary neopentyl alcohol 74. In this process, isopropanol serves as the hydrogen donor, and the isolated iridium complex prepared from [Ir(cod)Cl]2, allyl acetate, m-nitrobenzoic acid, and (S)-SEGPHOS is used as catalyst. Complete levels of catalyst-directed diastereoselectivity are observed. Exposure of neopentyl alcohol 74 to acetic anhydride followed by ozonolysis provides p-acetoxy aldehyde 75. Reductive coupling of aldehyde 75 with allyl acetate under transfer hydrogenation conditions results in the formation of homoallylic alcohol 76. As the stereochemistry of this addition is irrelevant, an achiral iridium complex derived from [Ir(cod)Cl]2, allyl acetate, m-nitrobenzoic acid, and BIPHEP was employed as catalyst (Scheme 5.9). 

A variation of this method led to the generation of bis-benzimidazoles [81, 82], The versatile immobilized ortho-phenylenediamine template was prepared as described above in several microwave-mediated steps. Additional N-acylation exclusively at the primary aromatic amine moiety was achieved utilizing the initially used 4-fluoro-3-nitrobenzoic acid at room temperature (Scheme 7.72). Various amines were used to introduce diversity through nucleophilic aromatic substitution. Cyclization to the polymer-bound benzimidazole was achieved by refluxing for several hours in a mixture of trifluoroacetic acid and chloroform. Individual steps at ambient temperature for selective reduction, cyclization with several aldehydes, and final detachment from the polymer support were necessary in order to obtain the desired bis-benzimidazoles. A set of 13 examples was prepared in high yields and good purities [81]. 

In contrast to the aforementioned monosubstitutions, much less is known about the effect of disubstitution. It appears that such benzamides are resistant to hydrolysis. The metabolic fate of nitromide (3,5-dinitrobenzamide, 4.63), a chicken-feed additive for the prevention of coccidosis, was investigated in rats. The metabolite 3-amino-5-nitrobenzoic acid (4.64), formed by ni-tro reduction and hydrolysis, was excreted in only trace amounts. Nitromide was metabolized mainly via nitro reduction [36], Similarly, no hydrolysis was... 

Reduction of 2-nitrobenzoic acid or the ester to the hydroxylamine stage in acid solution is accompanied by ring closure to form benzisooxazolone 20 [97]. When... 

Procaine Procaine, the 2-diethylaminoethyl ester of 4-aminobenzoic acid (2.1.1), better known as novocaine, is synthesized in two ways. The first way consists of the direct reaction of the 4-aminobenzoic acid ethyl ester with 2-diethylaminoethanol in the presence of sodium ethoxide. The second way of synthesis is by reacting 4-nitrobenzoic acid with thionyl chloride, which gives the acid chloride (2.1.2), which is then esterified with iV,Ar-diethylaminoethanol. Subsequent reduction of the nitro group by hydrogenation of the resulting ester (2.1.3) into an amino group takes place in the presence of Raney nickel [ 1 ]. 

Benzocaine Benzocaine is the ethyl ester of 4-aminobenzoic acid (2.3.1). The classic, optimal way of benzocaine synthesis is the reduction of the nitro group of the ethyl ester of 4-nitrobenzoic acid to benzocaine by hydrogen, which generates directly in the reaction medium by the reaction of iron filings with dilute acids [24-26]. 

Procainamide Procainamide, 4-amino-N-[2-(diethylamino)ethyl]benzamide (18.1.3), is synthesized by reacting 4-nitrobenzoic acid chloride with N,N-diethylethylendiamine and subsequent reduction of the nitro gronp of the resnlting 4-nitro-N-[2-(diethylamino)ethyl]ben-zamide (18.1.2) into an amino group [8,9]. 

The application of CPO, HRP and CiP is limited to sterically unencumbered substrates and all these peroxidases produce the same absolute configuration of the chiral hydroperoxide. To overcome this limitation, the semisynthetic enzyme selenosubtilisin, a mimic for glutathione peroxidase, with the peptide framework of the serine protease subtilisin was developed by Bell and Hilvert. This semisynthetic peroxidase catalyzes the reduction of hydrogen peroxide and hydroperoxides in the presence of 5-mercapto-2-nitrobenzoic acid. It was utilized by Adam and coworkers and Schreier and coworkers for the kinetic resolution of racemic hydroperoxides (equation 17) . The results obtained were very promising. 

The reduction to produce azoxy compounds appears to be successful for a wide range of aromatic nitro compounds. The following compounds, however, could not be reduced 1-nitronaphthalene, m-dinitrobenzene, 3,5-dinitroben-zoic acid (although o-, m-, and p-nitrobenzoic acids were reduced smoothly), compounds containing an amino group o-, orp- to a nitro group (except sodium... 

Nitrobenzoic acid chloride can be coupled to peptides in excellent yield, followed by reduction of the nitro function to the amine using either catalytic (Pd or Pt) hydrogenation t34,44-46 or tin(II) chloride. 33 This latter procedure has been applied to the solid phase. 41,42 A carbodiimide/HOBt coupling methodology has also been reported. 34 ... 

A related process, in which 2-aminoacetophenone is coupled with a 2-nitrobenzoic acid, a ketone, and an isocyanide, afforded 2-aryl-4,5-dihydro-l,4-benzodiazepin-5-ones in good to excellent overall yields after Fe-mediated reduction of the nitro group and ring closure <2005TL711>. 

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