3- Chloro-4- nitrobenzene, synthesis

Although acridone was not first synthesized by Lehmstedt, it was Lehmstedt who extensively explored the methods for the preparation of acridones, including the reaction between anthranilic acid and chloro-nitrobenzene, desulfurization of thioacridone by copper, and treatment of ortho-nitro benzaldehyde with chloro-nitrobenzene and sulfuric acid. Among these methods, the one between o-nitrobenzaldehyde and halobenzene is known as the Lehmstedt-Tanasescu method or Lehmstedt-Tanasescu reaction. In addition, this preparation of acridone is also referred to as the Tanasescu synthesis. ... 

Uses. (9-Nitrochlorobenzene is used in the synthesis of azo dye intermediates such as o-chloroaniline (Fast YeUow G Base), i9-nitroani1ine (Fast Orange GR Base), o-anisidine (Fast Red BB Base), o-phenetidine, and (9-aminophenol (see Azo dyes). It also is used in corrosion inhibitors, pigments, and agriculture chemicals. -Nitrochlorobenzene is used principally in the production of intermediates for azo and sulfur dyes. Other uses include pharmaceuticals (qv), photochemicals, mbber chemicals (qv), and insecticides (see Insectcontroltechnology). Typical intermediates manufactured from the para isomer are -lutioaruline (Fast Red GC Base), anisidine, -aminophenol, -nitrophenol, -phenylenediamine, 2-chloro-/)-anisidine (Fast Red R Base), 2,4-dinitrochlorobenzene, and l,2-dichloro-4-nitrobenzene. 

The profitable conversion of thiouronium salts into dialkyl thioethers (see Section 4.1) is less successful for synthesis of diaryl thioethers. For example, l-chloro-4-nitrobenzene reacts with bis-thiouronium salts of the type (H2N)2CS(CH2) SC(NH2)2+ under soliddiquid and liquidrliquid conditions to produce the desired bis-thioethers, ArS(CH2) SAr, (20-35%), together with the diaryl sulphide, Ar2S (5-15%). Higher yields of the diaryl sulphide are observed under liquiddiquid conditions whereas, under solidiliquid conditions, the diaryl disulphide, (ArS)2, (20%) is also formed [56], Diaryl disulphides are the sole products (>65%) from the stoichiometric reaction of aryl diazonium salts with benzyltriethylammonium tetrathiomolybdate [57],... 

An alternate and more controlled approach to the synthesis of phenothiazines involves sequential aromatic nucleophilic displacement reactions. This alternate scheme avoids the formation of the isomeric products that are sometimes observed to form from the sulfuration reaction when using substituted aryl rings. The first step in this sequence consists of the displacement of the activated chlorine in nitrobenzene (30-1) by the salt from orf/io-bromothiophenol (30-2) to give the thioether (30-3). The nitro group is then reduced to form aniline (30-4). Heating that compound in a solvent such as DMF leads to the internal displacement of bromine by amino nitrogen and the formation of the chlorophenothiazine (30-4). Alkylation of the anion from that intermediate with 3-chloro-l-dimethylaminopropane affords chlorpromazine (30-5) [31]. 

The nucleophilic displacement of halogens in aromatic compounds by fluorine is aided by utilizing an appropriate catalyst. Polymer-supported aminopyridinium salts have been found to be versatile catalysts for the synthesis of aryl fluorides. The advantage of the catalyst is that it can be recycled and used again. l-Chloro-4-nitrobenzene (3) is converted to l-fluoro-4-nitrobenzene (4) in 71 % isolated yield using this method. The catalyst used has the structure 5.91... 

A number of photochromic phenoxynaphthacenequinones were obtained using the initially synthesized 6-substituted ll-phenoxynaphthacene-5,12-quinones (IIIA) (Scheme 4).46 6,11-Dichloro-naphthacenequinone was the initial compound for the synthesis of these 6-chloro-ll-phenoxynaphthacenequinone compounds. 6-Chloro-1 l-tosylaminonaphthacene-5,12-quinone was obtained by interaction with phenox-ide potassium in DMSO and /j-tolucncsulfamidc in nitrobenzene, respectively. The latter compound was hydrolyzed in sulfuric acid to form 6-chloro-l 1-aminonaphtha-cene-5,12-quinone. The treatment of 6-chloro-l l-phenoxynaphthacene-5,12-quinone and 6-chloro-l l-aminonaphtacene-5,12-quinone with potassium phenoxide gave rise to 6-tosylamino- and 6-amino-ll-phenoxynaphthacene-5,12-quinones... 

Suggest a synthesis of the following compounds from the indicated starting material (a) l,.T5-lrichlorobenzene from aniline (b) 4-ch orobenzoic acid from aniline (c) l-chloro-4-nitrobenzene from aniline (d) 1-bromo-3-fluorobenzene from benzene (e) 3-chloroac-etanilide from benzene. 

ATR-FTIR/Raman Synthesis of tributyltin azide and hydrogenation of l-chloro-2-nitrobenzene to 2-chloroaniline [14]... 

A reasonable intermediate in the synthesis of vinclozolin is l-chloro-3-nitrobenzene. Starting from benzene,... 

Phosphorus pentachloride is used as a dehydration agent in preparing the key intermediate 2-chloro-3,5-dinitro-4-methylbenzonitrile 1446 from its carboxamide 1445 in 90% yield. 1446 is employed in the synthesis of hexasubstituted nitrobenzene derivatives 1447 [1099]. 

Ort/io-selectivity is generally observed in the reactions of 2,4-dichloro- and 2,4-difluoro-nitrobenzene with alkoxide and thiophenoxide ions [199]. Also in less activated systems, nucleophiles generated from phenols and thiophenols with potassium fluoride-alumina and 18-crown-6-polyether will react in DMSO with cyano- or nitro-substituted fluoro- or chloro-benzenes [200]. Interestingly, the reaction of difluorobenzenes with two diffoent alcohols can occur sequentially. Introduction of the first etho" function deactivates the ring, and use of more forcing conditions allows substitution of the second fluorine [201]. Consecutive displacements of fluorine and nitro groups have been observed in the reaction of ort/io-fluoronitrobenzene with chiral acyl bicyclic lactones in a highly enantioselective synthesis of spirooxindoles [202]. 

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