Cyclohexane nitroso

A nitrogen atom at X results in a variable downfield shift of the a carbons, depending in its extent on what else is attached to the nitrogen. In piperidine (45 X = NH) the a carbon signal is shifted by about 20 p.p.m., to ca. S 47.7, while in A-methylpiperidine (45 X = Me) it appears at S 56.7. Quaternization at nitrogen produces further effects similar to replacement of NH by A-alkyl, but simple protonation has only a small effect. A-Acylpiperidines show two distinct a carbon atoms, because of restricted rotation about the amide bond. The chemical shift separation is about 6 p.p.m., and the mean shift is close to that of the unsubstituted amine (45 X=NH). The nitroso compound (45 X = N—NO) is similar, but the shift separation of the two a carbons is somewhat greater (ca. 12 p.p.m.). The (3 and y carbon atoms of piperidines. A- acylpiperidines and piperidinium salts are all upfield of the cyclohexane resonance, by 0-7 p.p.m. 

Benzeneamine, N-hydroxy-N-nitroso, ammonium salt Cyclohexane 2,4-D... 

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. 

Since the question of the necessary conditions for isomerization of nitroso-cyclohexane to cyclohexanone oxime is of considerable commercial importance, it has been shown that this tautomerization is favored by the presence of gaseous hydrogen chloride, particularly at a wavelength of 300 mp. [57]. When cyclohexane is saturated with hydrogen chloride, treated with nitric oxide, and exposed to a source of ultraviolet radiation, the oxime forms along with a trace of 1-chloro-l-nitrosocyclohexane [58]. Cyclooctane seems to form the corresponding oxime and the chloronitroso compound, but under no circumstances nitrosocyclooctane [58]. 

In carbon tetrachloride at —30°C the product mixture consisted of 95% of trans-1 -chloro-2-nitrosocyclohexane dimer and 5% of trans-1 -nitro-2-nitroso-cyclohexane dimer. In trichloroethylene at —30°C, a 50-50 mixture of these two products was formed [15]. 

Nitro-compounds fRNOj) are isomeric with nitrites, but their electronic structure, excited states and photochemistry are very different. There is no very low-lying (n.jt ) state, and nitroalkanes show n — 3i absorption with a maximum around 275 nm ( —201 mol - cm In cyclohexane solution, nitromethane (CH1NOi) is photoreduced to nitrosomethane(CH,NO, but nitroethane under the same conditions gives rise to a nitroso-dimer derived from the solvent CS.47). The latter process is probably initiated by cleavage of the carbon-nitrogen bond in the nitroalkane. In basic solution (when the nitroalkane is converted to a nitronate anion) irradiation can lead to efficient formation of a hydroxamic acid (S.48), and this reaction most likely proceeds through formation of an intermediate three-mem bered cyclic species. 

Triaza Cyclohexane, 1,3-Dinitro-5-IUitroso (or NOX). See in Vol 7, H75-L under Hexa-hydro-1,3-dinitro-5-nitroso-5-triazine ... 

Although only a few hydrocarbons have been studied it appears that most of them react with OH with a rate constant of ca. 109 M-1 s 1. Methane is about 4 times less reactive than this value, and cyclopentane and cyclohexane about 5 times more reactive. Alcohols, amines, ethers, and many esters also fall in the same range. Carboxylic acids and carbonyl compounds seems to be to a certain degree less reactive. Lower reactivity is also found for the protonated forms of amines and amino acids. Direct reaction of OH with the substituent is usually unimportant except for a few cases such as thiols, where H is easily abstracted from the SH, or nitroso com-... 

Interesting solvent scales based on NMR measurements have been proposed by Taft et al. [90] and by Gutmann, Mayer et al [91]. A solvent polarity parameter, designated as P, has been defined by Taft et al [90] as the F chemical shift (in ppm) of 4-fluoro-nitrosobenzene in a given solvent, relative to the same quantity in the reference solvent cyclohexane cf. Table 6-6 and the discussion in Section 6.5.1). These parameters define a scale ranging from P = 0.0 in cyclohexane to P = 2.7 in sulfolane, and can easily be measured in a wide variety of solvents. The P values appear to be related to the ability of the solvents to form specific 1 1 complexes with the nitroso group of the standard compound. A compilation of P values can be found in reference [92], In addition, chemical shifts of (trifiuoromethyl)benzene and phenylsulfur pentafiuoride have been used by Taft et al. to study nonspecific dipolar interactions with HBD solvents and utilized to define n values of solvent dipolarity/polarizability for protic solvents [249]. 

Cyclohexadien 5-lsopropyl-2-methyl-3-nitro- V/lc, 163 Cyclohexan 1-lsopropenyl-4-methyl-4-nitroso-3-oxo- (dimer) X/l, 906f. 

Cyclohexan l-Chlor-l-isopropyl-2-nitroso-4-methyl- X/l, 933 f. Ethen 1-tert.-Butyloxy-2-chlor-l-morpholino-E15/2. 1859 (C13C-CH2-NR2 + R-OK)... 

Cyclohexan 4-Acetoxy-l-tert.-butyl-4-nitroso- (Isomerenge-misch) IV/ Jb, 260 Cyclopentan 3-Butyl-2-(2-nitro-propyl)-l-oxo- E16d, 231 (Michael-Addition)... 

Cyclohexan 5-tert.-Butyl-2,2-dimethoxy-l-nitroso- E16a, 966 (En + R-O-NO)... 

In a series of papers24a c, Oppolzer et al. introduced another procedure for the enantioselec-tive amination of enolates based on the A-acyl camphor sultam 1 as a chiral template and 1-chloro-l-nitroso cyclohexane (2) as electrophile. 

The ( )-dimer of ira ,y-l-nitroso-2-(l-piperidinyl)cyclohexane (1) was formed from cyclohexene and 1-nitrosopiperidine, accompanied by 2-(l-piperidinyl)cyclohexanone oxime (2). tra .v-Ar-Hydroxy-Ar-nitroso-2-(l-piperidinyl)-l-cyclohexanamine (3) was the predominant product in the presence of a 3-4 molar excess of A -nitrosopiperidine at — 40 °C in a Pyrex apparatus30,31. When a stream of oxygen was substituted for nitrogen, the reaction gave cis-and frans-/l-nitryloxyainines31. 

Kresze and cowoikers have used nitroso Diels-Alder reactions in synthesis of a variety of inosamines and related compounds. One example of this work is the synthesis of conduramine-Fl (92) as shown in equation (34). In this case, diene (91) reacted with a-chloro nitroso cyclohexane to afford adduct (91) as the only product. Just why this stereoisomer was formed is not obvious. Compound (91) could be converted to the conduramine in a few steps. 

Spectrophotometric methods based on ion associates with basic dyes are very sensitive. The Co-thiocyanate complex was associated with Malachite Green (CCI4 -i- cyclohexane), (e = 8.6-10 ) [61], Turquoise Blue (triphenylmethane dye) (toluene -1- DMF) [62], and 6-nitrodimethyline-carbocyanine [63,64]. The anionic complex of Co with chloro-oxine [65] associated with Rhodamine 6G was extracted with benzene. The complex of Co with 2-nitroso-l-hydroxynaphthalene-4-sulphonic acid was extracted into CHCI3 as the associate with a basic azo dye (e = 1.66-10 at 566 nm) [66]. 

Als Primarprodukte werden stcts die (monomeren) Nitroso-Verbindungen erhalten. Am Bei spiel des Cyclohexans zeigt die nachfolgende Ubersicht die verscbiedencn Reaktions-moglichkeiten ... 

Replacing the nitrosyl chloride by a mixture of nitric oxide and chlorine has also proved successful in the nitrosation of irradiated saturated hydrocarbons. According to the conditions and the proportions in which the oxide and chlorine are used, cyclohexane affords as main product 1-chloro-l-nitroso-cyclohexane, dimeric nitrosocyclohexane, or cyclohexanone oxime. Experimental details of this interesting reaction, which has industrial interest, will be found in a review by Muller et ah212 and the papers cited therein. 

Methods for synthesizing anisomycin and pentenomycin, ° and the chemistry and biological transformations of bleomycin and phleomycin have been reviewed.D-Ribo-furanosyl and -pyranosyl derivatives of iV-methyl-iV-nitroso-urea have been prepared as analogues of streptozotocin [2-deoxy-2-(JV-methyl-A -nitrosoureido)-D-glucose] they were reported to be more active against LI 210 leukaemia in mice and less toxic than the parent antibiotic. Likewise N- 2-chloroethyl)-iV-nitrosoureido derivatives of cyclopentane tetrols (35) and cyclohexane tetrols (36) have been synthesized for comparison with streptozotocin. ... 

---