Steroids, nitro

Acid catalysis is preferable to base for the condensation of 5a-cholestan-3-one (341) with pentyl nitrite to form the hydroxyimino-ketone (342). The dioxime (343) afforded the [2,3-c]furazan 2-oxide (344) on oxidation with hypochlorite. Nitration of the 3-ketone (341) with ethyl nitrate and base gave the 2-nitro-enol (345) the derived 3-oxime (346) gave the furazan oxide (344) on reaction with acid. Nitration of 5a-cholestan-7-one gave the 6a- and 6)5-nitro-ketones (347), apparently the first epimeric pair of steroidal nitro-ketones to be... 

The photooxygenation of (175) produced a ring ruptured compound (176) (Scheme 57) B-78MI41612) while similar treatment of steroidal isoxazolidine (177) resulted in the formation of two major nitro compounds also shown in Scheme 57 <77CC749). 

A -Steroids react sluggishly with nitrosyl fluoride to yield after alumina chromatography the nitro-olefin (44) (14 %), and 0.7 % of the 2a-fluoro ketone (45), the former probably arising by alumina-catalyzed dehydrofiuorination of an intermediate 2-fluoro-3-nitro adduct. 

Mechanism The reaction of and A -steroids with nitrosyl fluoride to form ni trimines is best discussed in conjunction with the nitrosyl chloride reaction leading tothe5a-chloro-6 -nitro steroids (33). Since nitroso alkanes are oxidized with nitrosyl chloride to nitro alkanes it is believed that 5a-chloro-6j5-nitro steroids are formed in this way from an initially formed 5a-chloro-6 -nitroso adduct. The same is true for nitrosyl fluoride up to the stage of the nitroso fluoride (56). Since NOF is a weaker oxidizing agent than NOCl the nitroso fluoride tautomerizes to the fluoro oxime (57) at a rate... 

The reaLUons of phenyltetrafluorophosphorane with numerous silylated secondary or tertiary a- or (1-hydroxy esters, ketones, nitriles, ethers, nitro, and trichloromethyl derivatives have been investigated, the corresponding a or p fluoro derivatives are obtained in yields varying from reasonable to nearly quantitative [24, 25, 26, 27 The application of phenyltetrafluorophosphorane for fliiorination of silyloxy steroids has also been reported [28]... 

The sequence (81 84) has been proposed - to account for this process which involves decomposition of the aci-nitro anion by strong acid. The a-carbonyl group presumably stabilizes the aci-salt and thus could be responsible for inhibiting the normal Nef reaction. A similar transformation has been observed in the case of a 16-nitro-17-0X0 steroid. 

The y-lactone ring of the steroid skeleton forms an intermediate cardenohde anion in alkaline medium that nucleophilically adds to the 3,5-dinitrobenzoic acid in the position ortho to the two nitro groups. A mesomerically stabilized red-violet anion is produced (Meisenheimer complex). 

The steroids aldosterone, cortisone, cortisol, 11-P-hydroxyandrostenedione, corticosterone, and rostenedione, 11-desoxycorticosterone, 17-hydroxy-progesterone, and progesterone have been performed on Ultrasphere ODS using methanokwater.19 Ranitidine N-[2-[[[5-[(dimethylamino)methyl]-2-furanyl]-methyl]thio]ethyl]-N1-methyl-2-nitro-l,l-ethenediamine has been separated using a p-Bondapak C18 column operated with acetoni-trile methanol water buffered with triethylamine phosphate.117 Pyridoxal-5 -phosphate and other B6 vitamers, including pyridoxamine phosphate, pyri-doxal, pyridoxine, and 4-pyridoxic acid, were separated as bisulfite adducts... 

Photolysis reactions often are associated with oxidation because the latter category of reactions frequently can be initiated by light. The photooxidation of phenothiazines with the formation of N- and S-oxides is typical. But photolysis reactions are not restricted to oxidation. In the case of sodium nitroprusside, it is believed that degradation results from loss of the nitro-ligand from the molecule, followed by electronic rearrangement and hydration. Photo-induced reactions are common in steroids [36] an example is the formation of 2-benzoylcholestan-3-one following irradiation of cholest-2-en-3-ol benzoate. Photoadditions of water and of alcohols to the electronically excited state of steroids have also been observed [37],... 

Thiemann and coworkers [68] sought novel types of steroids with different biological activity, and in doing so prepared areno-annulated compounds such as 6/1-133 (Scheme 6/1.35). This is achieved with a Heck reaction of 6/1-132 with an acrylate, followed by an electrocydic ring closure of the formed hexatriene. The reaction is then terminated by removal of the nitro group, with formation of the aromatic ring system. 

Iodotrimethylsilane generated in situ from chlorotrimetylsilane and sodium iodide effects the reduction of nitroalkenes into ketones at 0 °C. This method is useful for the conversion of nitro steroids or nitro terpenoids to the corresponding ketones (Eq. 6.24).43... 

Photolysis of nitro-steroids 225 yields the aci-nitronate at 254 nm131. This in turn gives various products, among them are ketone 226 and hydroxamic acid 227 (equation 105) which could be formed from the intermediate anions of the Af-hydroxyoxaziridines, with a possible participation of gem-hydroxynitroso transient (or its anion see Scheme 10). For comparison, IV-butyl spiro-oxaziridine 228 in ethanol is photolysed at 254 nm (equation 106) to give 7V-butyl lactam 229 (50%) and the ketone 230 (25%). The former process is a well-known photoprocess of oxaziridine131. 

Both 2-nitro steroids 235 and 239 exist as the enols in ethanol, and are photolysed to give the corresponding a-diketones 237 and 238 (23% in 1 1 ratio)133 (equation 108) and 240 (equation 109), but different monoxime 236 and 241, respectively. On the contrary, 4-nitroketone 242 exists in the keto form, and is photolysed to give the a-oximino ketone 243 and its tautomer 244 without the diketones (equation 110). 

Amino substituents in acyclic derivatives have been discussed by Eggert and Djerassi (396), who emphasize structural and conformational effects, whereas Batchelor has investigated SCS(NH2) and nitrogen protonation shifts in methylated cyclohexylamines (424). The, 3C NMR spectra of amino acids have been compared with those of amines and carboxylic acids (425,426). The transmission mechanisms of amino, ammonium, trimethylammonium, acetamido, and di-acetamido groups have been examined by Faure and co-workers (427), the SCSs of nitro groups by Ejchart (400), and those of azido functions in steroids by Lukacs and co-workers (428). 

Polymers and resins Water purification, including removal of phenol, chlorophenols, ketones, alcohols, aromatics, aniline, indene, polynuclear aromatics, nitro- and chlor-aromatics, PCB, pesticides, antibiotics, detergents, emulsifiers, wetting agents, kraftmill effluents, dyestuffs recovery and purification of steroids, amino acids and polypeptides separation of fatty adds from water and toluene separation of aromatics from ahphatics separation of hydroquinone from monomers recovery of proteins and enzymes removal of colours from symps ... 

TRICYCLIC ANTIDEPRESSANTS 11 AVERMECTINS 12 CARDIAC DRUGS 13 IBUPROFEN 14 CHL0R0-, NITRO-PHENOLS 15 TESTOSTERONE STEROIDS... 

Samajdar et al. (2000) performed nitration of aromatic compounds by bismnth nitrate on catalysis with montmorillonite KSF. The reaction develops in THF suspension on steering dnring 10 min. Nitration of anisole proceeds strictly in the para position (91% yield after 10 min), bnt in case of phenol, the reaction occnrs to be nonregioselective and 3 1 mixture of para and ortho nitro prod-nets is formed with a common yield of 89%. Nitration of estrone (the steroid phenol) also leads to 1 1 mixtnre of para and ortho nitrophenolic steroids in 94% yield. 

Photoexcited nitrobenzene may be used for benzylic hydroxylation (at C-9) of 17/3-acetoxy-3-methoxyoestra-l,3,5(10)-triene. The photochemistry of the 17/3-nitro-steroid (217) is markedly solvent dependent, the major products being in ether the 17-desnitro-compound (218), in propan-2-ol the hydroxylamine (219), and in EtOH-NaOEt the hydroxamic acid (220) and the cyclopropane (221). The hydroxamic acid (220) is probably formed through the oxaziridine (Scheme 7). Although there are analogies to this in the photochemistry of nitrones and oximes, the photoreduction of a nitroalkane in propan-2-ol to an alkyl-hydroxylamine appears to have no precedent. Further studies of photochemistry of conjugated... 

Oxo-steroide lassen sich unter Stereokontrolle mit Trifluoracetylnitrat, hergestellt aus Tri-fluor-essigsaure-anhydrid und Ammoniumnitrat, iiber die intermediar entstehenden O-Tri-fluoracetyl-enole in fast quantitativer Ausbeute in die entsprechenden a-Nitro-oxo-steroide iiberfuhren1 z. B. ... 

A representative of the second group is the hydrolysis of 3,5-dinitro-benzoic acid esters of hydroxysteroids. The waves of the nitro-groups in the steroid ester are significantly smaller than those of 3,5-dinitrobenzoic acid, and the hydrolysis has been followed by the increase in the wave-height with time (18). 

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