Ethanol, 2-Chloro-2-nitro

Dipping sointion II Dissolve 0.1 g NBD-chloride (7-chloro-4-nitrobenzofurazan, 7-chloro-4-nitro-2,l,3-benzoxadiazole) in 50 ml ethanol. 

Ethane, 1-chloro-l-nitro-, 37, 25 1,2-Ethanedithiol, 30, 35 Ethanol, 2,2-dichloro-, 32, 46 Ethanolysis, 33, 25 Ether, benzhydryl 2-chloroethyl,... 

Diaminopyridine has been prepared by reduction of 2-amino-3-nitropyridine with iron and aqueous acidified ethanol,3 tin and hydrochloric acid,6 or stannous chloride and hydrochloric acid,6 by catalytic reduction of 3-amino-2-nitropyridine,6 by reduction of 3-amino-2-nitropyridine,7 2-amino-5-chloro-3-nitro-pyridine,8 or 2-amino-5-bromo-3-nitropyridine 4 with sodium hydroxide solution and an aluminum nickel alloy, and by catalytic reduction of 2-amino-5-bromo-3-nitropyridine.4 Animation of... 

It is an explosive. Can be prepd by nitrating either 2-(5 -chloro-2 -nitro-anilino)-ethanoI or 2-(5 -chIoro-2, 4 -dinitro-anilino)-ethanol with absolute nitric acid at —10°... 

Catalytic hydrogenation of 6-chloro-8-nitro-3,4-dihydro-2//-pyrimido-[l,2-a]isoquinoline in ethanol over Pt02 for 69 h afforded 8-amino-3,4-di-hydro-2H-pyrimido[l,2-a]isoquinoline (67IJC403). 

Although the simple aryl halides are inert to the usual nucleophilic reagents, considerable activation is produced by strongly electron-attracting substituents provided these are located in either the ortho or para positions, or both. For example, the displacement of chloride ion from l-chloro-2,4-dinitrobenzene by dimethylamine occurs readily in ethanol solution at room temperature. Under the same conditions chlorobenzene completely fails to react thus the activating influence of the two nitro groups amounts to a factor of at least... 

Formation of a symmetrical sulphide (a) (e.g. dipropyl sulphide, Expt 5.204), is conveniently effected by boiling an alkyl halide (the source of carbocations) with sodium sulphide in ethanolic solution. Mixed sulphides (b) are prepared by alkylation of a thiolate salt (a mercaptide) with an alkyl halide (cf. Williamson s ether synthesis, Section 5.6.2, p. 583). In the case of an alkyl aryl sulphide (R-S Ar) where the aromatic ring contains activating nitro groups (see Section 6.5.3, p. 900), the aryl halide is used with the alkyl thiolate salt. The alternative alkylation of a substituted thiophenol is described in Section 8.3.4, p. 1160. The former procedure is illustrated by the preparation of isobutyl 2,4-dinitrophenyl sulphide (Expt 5.205) from l-chloro-2,4-dinitrobenzene and 2-methylpropane-1-thiol. 

A mixture of 6.65 g of 3-chloro-6-nitroacetanilide, 3.2 ml of propylmercaptan, 5.6 g of 50% sodium hydroxide and 100 ml of water is heated at reflux overnight. The cooled mixture is filtered to give the desired 2-nitro-5-propylthioaniline, MP 69.5-71.5°C after recrystallization from ethanol then hexane-ether. NMR (CDCI3) 40%. 

As has already been noted in the section on ethanol deaminations, upon diazotizing some nitroamines in hydrochloric acid, a diazonium salt is obtained in which the nitro group has been replaced by chlorine (pp. 272-273). Consequently, hypophosphorous acid reduction gives a deaminated product Containing chlorine in place of the nitro group. For example, when 5-amino-8-nitroisoquinoline (XVIII) is diazotized with hydrochloric acid and then treated with hypophosphorous acid, 8-chloro-isoquinohne (XIX) is obtained in 60-70% yield instead of 8-nitro-isoquinoline.86... 

The synthesis of pazopanib (1) involves sequential animation of 2,4-dichloropyrimidine 25 with 6-amino-2,3-dimethylindazole 24 and 5-amino-2-methyl-benzenesulfonamide 28. The 6-amino-2,3-dimethylindazole 24, on the other hand, was prepared from 2-ethylphenylamine 20 via 5-nitration with fuming nitric acid and concentrated sulfuric acid, followed by treatment with isoamyl nitrite and acetic acid to produce 6-nitro-3-methylindazole 22. The 6-nitro group was reduced with stannous chloride and concentrated HC1 in glyme and subsequently methylated at the C2 position of the indazole ring with trimethyloxonium tetrafluoroborate in acetone to produce 6-amino-2,3-dimethylindazole 24. The resultant indazole 24 was condensed with 2,4-dichloropyrimidine 25 in the presence of sodium bicarbonate in ethanol/THF and subsequent iV-methylation with iodomethane and cesium carbonate to produce 27. The 2-chloro group of pyrimidine was then allowed to react with 5-amino-2-methyl-benzenesulfonamide 28 in catalytic HCl/isopropanol and heated to reflux to deliver pazopanib hydrochloride (1) in good yield. 

Cyclization at the hydroxylamine also occurs in the hydrogenation of l-nitro-2-thio-cyanatobenzene (30) to give 2-aminobenzothiazole 3-oxide (31) (Scheme 9.14).157 The hydrogenation over Raney Ni in ethanol at room temperature and 0.3 MPa H2 was complete after several hours with absorption of 2 mol of hydrogen to give crude 31 in 75-88% yield. The infrared spectrum of the product 31 indicated the presence of an equilibrium between 31a and 31b. Under similar conditions but with use of platinum oxide in tetrahydrofuran, 31 and its 5-methyl, 5-methoxy, and 5-chloro derivatives... 

There is little recent information in this area. The tine structure of 3-acetoxy-l, 4-dinitro-2-piperazinol (14) has been elucidated by X-ray analysis.1212 Treatment of 5,6-dichloro-3-nitro-2-pyrazinamine (15) with refluxing ethanolic sodium cyanide for 4 days induced displacement of the nitro by a cyano group as well as ethanoly-sis of one chloro substituent to afford 3-amino-6-chloro-5-ethoxy-2-pyrazinecar-bonitrile (16) in 55% yield.1313 L-Methyl-4-(/>nitrobenzoyl)pipcrazine (17) gave I -(/ -aminobenzoyl)-4-methy I piperazine (18) (75%) on refluxing in ethanolic hydrazine hydrate with a little Raney nickel catalyst for 6 h 135, cf 1032 other reduction procedures have been reported.496,1741... 

As already indicated in Section III,A, nucleophilic attack easily occurs at positions ortho and para to the ring nitrogen and/or the nitro group. Amino-dehalogenation in halogeno-3-nitronaphthyridines has been extensively studied and a number of amino-3-nitronaphthyridines (961-96v) were obtained by the action of ethanolic ammonia on the 2- and 4-chloro-3-nitronaphthyridines (96a-96k). 

Nitro groups, which are readily introduced into the imidazole ring,269,388 445 can be reduced chemically or catalytically to amino groups.227,446 Nitro substituents facilitate the displacement of adjacent halogen substituents,447 e.g., the chloro group of 5-chloro-4-nitroimidazole can be replaced by an alkylmercapto group using sodium alkylmercaptide and sodium ethoxide in ethanol. 

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