V- hydroxylamine

B. Mix 1 drop or several small crystals (ca. 0 05 g.) of the compound with 1 ml. of 0-5 V hydroxylamine hydrochloride in 95 per cent, ethanol and add 0-2 ml ot aqueous sodium hydroxide. Heat the mixture to boiling and, after the solution has cooled slightly, add 2 ml. of N hydrochloric acid. If the solution is cloudy, add 2 ml. of 95 per cent, ethyl alcohol. Observe the colour produced when I drop of 6 per cent, ferric chloride solution is added. If the resulting colour does not persist, continue to add the reagent dropwise until the observed colour pervades the entire solution. Usually only 1 drop of the ferric chloride solution is necessary. Compare the colour with that produced in test. 4. A positive test will be a distinct burgundy or magenta colour as compared with the yellow colour observed when the original compound is tested with ferric chloride solution in the presence of acid. 

The most advanced PDF inhibitor to emerge thus far from this collaboration is LBM-415 (12) (also called NVP PDF-713 or VIC-104959), an V-formyl-V-hydroxylamine compound still containing a proline residue at P2. The activity, PK properties, and in vivo efficacy data of (12) were presented at the 14th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) (2004) and the structure of this... 

Nitrones have been generally prepared by the condensation of /V-hydroxylamines with carbonyl compounds (Eq. 8.40).63 There are a number of published procedures, including dehydrogenation of /V,/V-disubstituted hydroxylamines, / -alkylation of imines, and oxidation of secondary amines. Among them, the simplest method is the oxidation of secondary amines with H202 in the presence of catalytic amounts of Na2W04 this method is very useful for the preparation of cyclic nitrones (Eq. 8.41).64... 

V. HYDROXYLAMINES THROUGH ADDITION TO THE C=N DOUBLE BOND OF OXIMES, OXIME ETHERS AND NITRONES... 

The potassium permanganate impinger solutions. Any permanganate stain remaining in the impinger shell was removed with a few drops of 10% w/v hydroxylamine hydrochloride followed by a rinse with distilled water. These rinses were added to the permanganate in the sample bottle. 

Equilibrium496 and kinetic497 studies have also been reported for the vanadium(v)-hydroxylamine system. The complex V02NH30H is suggested to be the major... 

Reagents. Sulphuric acid (18 N), nitric acid (sp. gr. 1.42), potassium permanganate 5% (m/v) solution, potassium persulphate 5% (m/v) solution, sodium chloride 12% (m/v)—hydroxylamine sulphate 12% (m/v) solution. 

Synthesis of Chiral Reagents. An efficient chiral a-chloro-a-nitroso reagent derived from 10-camphorsulfonyl chloride (1, Cy2NH 2, NH2OH 3. t-BuOCl 70-78%) has been developed for the asymmetric a-amination of ketone enolates (eq 7). The resulting p-keto /V-hydroxylamine can be converted to the anti-1,2-hydro y amine under reducing conditions (NaBHt Zn, HCl, AcOH),... 

In primary aliphatic amines, such as phentermine. chlorphentcrmine (yx-chlotphentcrmine).- and amantadine. N-oxidation appears to be the major biotransformation pathway because a-carbon hydroxylation cannot occur. In hum-ans. chlorphentcrmine is N-hydroxylated extensively. About 30% of a dose of chlorphentermine is found in the urine (48 hours) as Al-hydroxychlorphentermine (free and conjugated) and an additional 18% as other products of N-oxidation (presumably the nitroso and nitro metabolites). In general, /V-hydroxylamines are chemically unstable and susceptible to spontaneous or enzymatic oxidation to the nitro.so and nitro derivatives. For example, the N-hydroxyl-amine metabolite of phentermine undergoes further oxiila-... 

Allyl or benzyl groups on the nitrogen facilitate the process. The rearrangement appears to be intramolecular (13), proceeding by a cycHc mechanism as in the case of /V-2-buteny1-/V-metby1 aniline oxide giving /V-methyl-0-1-methylallyl-/V-phenyl-hydroxylamine. 

The chemical consequences of /3-protonation are illustrated further by the ring-opening reactions of furans with methanolic hydrogen chloride and of (V-substituted pyrroles with hydroxylamine hydrochloride (Scheme 11) (82CC800). 

The action of hydroxylamine and sodium acetate in ethanol upon picryl chloride was stated to give 4,6-dinitrobenzofuroxan, and probably some of this compound was formed, although it was later shownthat much of the original work was faulty. A report that hydroxylamine and 2,4,5-trinitrotoluene give 5-methyl-6-nitro-benzofuroxan has been found to be incorrect. Benzofuroxan has not been prepared by V-oxidation of benzofurazan, and it seems unlikely that this could be achieved, since benzofuroxan itself is oxidizable by powerful reagents to o-dinitrobenzene (Section VI, B). A report of the oxidation by nitric acid of anthraceno[l,2-c]furazan to the furoxan is incorrectlv abstracted. 

The hydroxy group of furazan 263 reacted with cyanogen bromide in glyme in the presence of Li2C03 to give cyanate 264 in 70-85% yield (97MI8). Upon treatment with Mc4NN3 and subsequently with a basic solution of hydroxylamine-0-sulfonic acid, /V-aminotetrazole 265 was obtained in 35% yield (Scheme 171). 

A -Benzoyl-i V-phenyl hydroxylamine 440 Nebuliser-burner system 785 Neocuproin 178... 

Singlet phenylnitrene, and hence /V,A -diethyl-3//-azcpin-2-amines, e. g. 102, can be generated by the thermolysis of A,-phenyl-Af,<9-bis(trimcthylsi]yl)hydroxylamine (100) in the presence of dialkylamines the reaction fails, however, with arylamines.210 Photofragmentation of the spiro oxaziridine 101 in diethylamine solution also produces the 3//-azepine 102,2,1 and an oxaziridine intermediate is probably involved in the formation, in low yield (1 %), of azepine 102 by the photolysis of A/,A( -diarylbenzoquinonc diimine A/,A/ -dioxides in benzene/die-thylamine solution.212... 

Treatment of 2- 5//-dibenz[i>,/]azepin-5-yl acetaldehyde (16), prepared in 68% yield by /V-alkylation of 5/7-dibenz[A,/]azepine with bromoacetaldehyde diethyl acetal followed by acid hydrolysis, with methyl hydroxylamine yields the isolable nitrone 17, which in refluxing toluene undergoes intramolecular 1,3-dipolar cycloaddition at the CIO —Cl 1 alkene bond to give 2,3,3a, 12b-tetrahydro-2-methyl-3,8-methano-8//-dibenz[i>,/]isoxazolo[4,5-r/]azepine (18).235... 

Hydroxylamine, O-acetyl-A -benzoyl-.V-phenyl-hydroxamic acids from, 2, 506... 

Hydroxylamine, IV-benzoyl-lV-phenyl-in gravimetry, 1, 532 liquid-liquid extraction, 1, 544 Hydroxylamine, A -cinnamoyl-A -phenyl-liquid-liquid extraction, 1,544 Hydroxylamine, Ar,A -di-(-butyl-metal complexes, 2, 798 Hydroxylamine, Ay/V-diethyl-metal complexes, 2,798 Hydroxylamine, AAmethyl-metal complexes, 2,798 Hydroxylamine, A -2-naphthol-A -nitroso-ammonium salt — see Ncocupferron Hydroxylamine, A -nilrosophenyl-ammonium salt — see Cupferron Hydroxylamine ligands, 2, 101 Hydroxylamine oxido reductase, 6, 727 Hydroxylases molybdenum, 6,658,662 Hydroxylation arenes... 

The most widely employed methods for the synthesis of nitrones are the condensation of carbonyl compounds with A-hydroxylamines5 and the oxidation of A+V-di substituted hydroxylamines.5 9 Practical and reliable methods for the oxidation of more easily available secondary amines have become available only recently.10 11 12 13. These include reactions with stoichiometric oxidants not readily available, such as dimethyldioxirane10 or A-phenylsulfonyl-C-phenyloxaziridine,11 and oxidations with hydrogen peroxide catalyzed by Na2W044 12 or Se02.13 All these methods suffer from limitations in scope and substrate tolerance. For example, oxidations with dimethyldioxirane seem to be limited to arylmethanamines and the above mentioned catalytic oxidations have been reported (and we have experienced as well) to give... 

Geminale Chlor-nitroso-Verbindungen werden durch Lithiumalanat in Diathylather (40-70% d.Th.) oder besser mit Natriumboranat in waBrigem Athanol (50-80% d.Th.) zu Oximen reduziert. Als Nebenprodukte konnen gelegentlich Hydroxylamine isoliert werden. So erhalt man z.B. aus 1-Chlor-l-nitroso-cyclohexan mit Natriumboranat neben 61 % d.Th. Cyclohexanon-oxim 11 % d.Th.V-Cyclohexyl-hydroxylamin5. Dagegen werden bei der Reduktion von 1-Nitroso-l-acetoxy-cyclohexan Cydohexanol (8% d.Th.) und N-Cyclohexyl-acetamid (34% d.Th.) erhalten6. 

In basischer Pufferlosung lassen sich bei -1 V aus Nitro-alkoxy(aryloxy)-benzolcn se-lektiv die Hydroxylamine herstellen in schwach saurem Milieu (Acetatpuffer, bei -1,6 V) erhalt man Amine. In starker saurem Milieu entstehen aus den 4-AIkoxy-Derivaten unter Atherspaltung Amino-phenole6 ... 

In alkoholischer Acetatpuffer-Losung konnen 2-Nitro-l-(2-nitro-phenyl)-athanole bei -0,5 V zur Hydr-oxylamin-Verbindung I und bei - 1,2 V zum Bis-hydroxylamin reduziert werden. Der RingschluB zum Cinnolin wird durch Luftsauerstoff verursacht1 ... 

Die Reduktion von N-Hydroxy-piperidin zu Piperidin (82% d. Th.) in 0,2 m waBr. Oxalsaure ist als indi-rekte elektrolytischc Reduktion anzusehen, weil das gleichzeitig anwesendc Titan(IV)-chlorid bei -0,5 V zu Titan(III) reduziert wird, das dann scinerseits das Hydroxylamin reduziert. ... 

Hydroxylamines, V-substituted, 58,108 Hydroxylation with thallium(l) acetate,... 

Methyl-2-quinoxalinecarbaldehyde 1,4-dioxide (235) and (V-(2-chloroethyl)-hydroxylamine hydrochloride (236) gave the nitrone, 2-(2-chloroethylimino-methyl)-3-methylquinoxahne 1,4,/V-trioxide (237) (NaHC03, 95% EtOH, warm then 20°C, 1 h 70% after separation from a byproduct).703... 

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