Nitro startg

A suspension of 5-nitro-isatoxime in alcohol-coned. HC1 treated with Sn, and, towards the end of the reaction, heated until dissolved 3,5-diamino-oxindole dihydrochloride (startg. m. f. 190). Y 90%. (E. Giovannini and P. Portmann, Helv. 31,1381 (1948).)... 

A soln. of the crude startg. m. in pyridine containing acetic anhydride kept 0.5 hr. at room temp. -> 3-0-acetyl-5,6-dideoxy-l,2-0-isopropylidene-6-nitro-a-D- y/o-hex-5-enofuranose. Y 80%. W. A. Szarek, D. G. Lance, and R. L. Beach, Carbo-hyd. Res. 13, 75 (1970). 

Almost 2 equivalents H2O2 and coned. HCl added at 5-10° to a soln. of the startg. m. in acetic acid, and kept overnight at the same temp. -> methyl 6-chloro-ll-nitro-7-oxo-O-methylpodocarpate. Y 80%. F. e. s. B. Kumar and S. Kalra, J. Indian Chem. Soc. 50, 613 (1973) with metal halides in place of HCl, a-balogeno-carbonyl compds., cf. N. Inukai et al., Chem. Pharm. Bull. 24, 820 (1976). 

A novel insoluble green complex of palladium(II) and N,N -salicylideneethylenedi-amine (salen) functions as a selective heterogeneous catalyst, notably for the reduction of alkynes in the presence of alkenes, and of the latter in the presence of certain functional groups. E ciVEthylene from acetylene derivs. A soln. of startg. acetylene deriv. in EtOH hydrogenated for 17 min in the presence of the palladium(ll) complex (prepared from potassium tetrachloropalladate, salen, and triethylamine) cis-product. Y 100%. Reduction of alkenes is considerably slower however, terminal olefins may be reduced in the presence of internal olefins esters, oxo compds., dibenzyl ether, and iodobenzene were unaffected. F.e., also ar. amines from nitro compds. s. J.M. Kerr et al.. Tetrahedron Letters 29, 5545-48 (1988). 

A mixture of startg. acid chloride and (o-dimethylaminomethylphenyl)phenylsilane allowed to react until reaction complete (method cf. Synth. Meth. 43, 76) - product. Y 80%. Wet silica gel retains the chlorosilane by-product before distillation of the aldehyde. The method is quick, selective and high-yielding, and work-up is simple esters, halides, ethers, olefins and nitro groups remained unaffected. F.e., work-up procedure, and reagents s. R.J.P. Corriu et al.. Tetrahedron Letters 29,1271-4 (1988). 

Acoxy-2-pyrone ring. 7-Nitrofluorene-l,9-dicarboxylic acid refluxed with acetyl chloride until after ca. 3 days the startg. m. has disappeared crude 9-nitro-l-acetoxy-2-oxa-3-oxo-2,3-dihydrofluoranthene. Y 89%. R. Kuhn and U. Breyer, B. 95, 111 (1962). 

Methyl-4(5)-nitroimidazole added to a soln. of Na in methanol, evaporated to dryness, and the resulting Na-salt refluxed 2 hrs. in a mixture of isopropyl iodide and dimethylformamide -> 12 g. l-isopropyl-2-methyl-4-nitroimidazole. - The 5-nitro isomer was obtained by refluxing the above startg. m. with 2-propyl tosylate in benzene. M. Hoffer et al., J. Med. Chem. 14, 993 (1971). 

Startg. bromide added dropwise at 15-20° to a stirred soln. of 2 moles Na-nitrite in dimethylformamide, and stirring continued 4 hrs. at room temp, after heat evolution has subsided 3-nitro-5-phenylisoxazole. Y 63%. F. e. with lower yields s. S. Rossi and E. Duranti, Tetrah. Let. 1973, 485. 

A soln. of the startg. m. in coned. H2SO4 cooled to < 5°, stirred and treated in one portion with nitrosyl sulfuric acid prepared from NaNO and coned. H2SO4, stirred 1 hr. at 0-5 , the cooling bath removed, and stirring continued 1 hr. 2-ethyl-7-nitro-2,3-dihydroimidazo[l,2-f]phenanthridine. Y 80%. F. e. s. H.-L. Pan and T. L. Fletcher, J. Heterocyclic Chem. 9, 859 (1972). 

A soln. of 2-nitro-l-r rf-butylbenzene in methanolic-aq. NaOH irradiated 5 hrs. at 20° under N2 with a 70 w. high-pressure Hg-lamp l-hydroxy-3,3-dimethyl-3H-indol-2-one. Y 66% based on startg. m. consumed startg. m. recovered 86.8%. D.Dopp, B. 104, 1035 (1971). 

Cyclohexanol added at 18-20° to 6 parts 65-66%-HNO3 at such a rate that no startg. m. accumulates 6-nitro-6-(hydroxyimino)hexanoic acid. Y 97-8%. Z. S. Smolyan et al., Khim. Prom-st 1975, 266 C. A. 83, 58030. 

A soln. of 5-nitro-2-furancarboxaldehyde and the startg. hydantoin deriv. in coned. HCl refluxed 1 hr., coned, under reduced pressure, benzene added to the solid residue, and again coned, to a solid 5-hydroxy-l- [(5-nitro-2-furanyl)meth-ylene]amino)hydantoin. Y 88%. R. L. White, S. E. Burrous, and T. J. Schwan, J. Pharm. Sci. 66, 111 (1977). 

Benzoxylamine and powdered anhydrous Na-acetate added to a soln. of 2-amino-4-chloro-5-nitro-6-methylpyrimidine in ethanol, and refluxed 1 hr. 2-amino-4-benzoxylamino-5-nitro-6-methylpyrimidine (startg. m. f. 20). Y 78%. E. G. Taylor and J. W. Barton, J. Org. Ghem. 24, 127 (1959). 

Raney-Ni W 2 added at 0-5 to a suspension of czs-l-nitro-2-phenylcyclohexane in ethanol, and hydrogenated 140 min. under 50 p.s.i. whereby room temp, is gradually reached -- crude czs-l-amino-2-phenylcyclohexane. Y 76% as the phenylthioureide.— When the startg. m. is dissolved in ethanol at 60-70°, a mixture of cis- and trans-isomers results. Thus, the hydrogenation proceeds with retention of configuration if conditions are used that avoid epimerization of the nitro group prior to reduction. F. G. Bordwell and R. L. Arnold, J. Org. Chem. 27, 4426 (1962). 

Finely powdered D-arabo-tetraacetoxy-l-nitro-l-hexene added portionwise with shaking to abs. methanol satd. with anhydrous NHg at 0°, then allowed to stand 18 hrs. at 5 1-nitro-l-deoxy-N-acetyl-D-mannosaminol (startg. m. f. 258). Y 82%. A. N. O Neill, Gan. J. Chem. 37, 1747 (1959). 

O-Acetylation. 1-Nitro-l-deoxy-N-acetyl-D-mannosaminol (prepn. s. 396) dissolved at 5° in 2 iV NaOH, added dropwise with shaking and cooling at 5-15° to aq. H2SO4, neutralized with warm Ba-hydroxide soln., filtered, 2 drops of acetic acid added, coned, under reduced pressure, and the crude product kept 3 days at 0° with acetic anhydride and pyridine 2-acetamido-2-deoxy-l,3,4,6-tetra-O-acetyl- -D-mannose (startg. m. f. 7). Y 84%. A. N. O Neill, Can. J. Chem. 37, 1747 (1959) Nef reaction and N-deacetylation with HCl s. J. C. Sowden and M. L. Oftedahl, Am. Soc. 82, 2303 (1960). 

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