Methanol imines

Adsorption of 19a on CdS was measured from methanolic solution. As observed for the adsorption of 2,5-DHF, the adsorption isotherm indicates the presence of mono- and multilayer adsorption. From the former a maximum surface concentration eq(max) of 20 X 10 mol g Can be estimated. At higher concentrations a linear correlation seems to be present. A similar behavior was observed also for the adsorption of chlorophenols on Ti02 [46]. Application of the Fliemenz model on the methanol-imine surface monolayer leads to an adsorption constant of 4400 + 950 and a <7° value of 4000 A. This is far too large, as indicated by comparison with 50 (14 x 3.5 A) estimated for a flat unsolvated molecule. This... 

Figure 5. Normal Pulse voltammogram (20 s step time 10 s pulse width) for methanol (IMin IM H O/aq)) oxidation at glassy carbon rotating (1500 rpm) disc eleclrwies coated with 35%Pi-Ru (0.10 mg cmr 1.3 1 Pt.Ru) on PEDOT/PSS in a Nafion matrix.

Amin omethyl-3,5,5-trimethyl cyclohexyl amine (21), commonly called isophoronediamine (IPD) (51), is made by hydrocyanation of (17) (52), (53) followed by transformation of the ketone (19) to an imine (20) by dehydrative condensation of ammonia (54), then concomitant hydrogenation of the imine and nitrile functions at 15—16 MPa (- 2200 psi) system pressure and 120 °C using methanol diluent in addition to YL NH. Integrated imine formation and nitrile reduction by reductive amination of the ketone leads to alcohol by-product. There are two geometric isomers of IPD the major product is ds-(22) [71954-30-5] and the minor, tram-(25) [71954-29-5] (55). 

There is some evidence for the formation of unstable benzazetidines from [2 + 2] cycloaddition of benzyne to imines (75BCJ1063). A novel formation of a benzazetidine is reported in the solvolysis of the exo iV-chloro compound (297). Neighbouring group participation by the benzene ring leads to the cation (298), which is intercepted by methanol to give the benzazetidine (299) (81CC1028). 

However, when the addition is performed 111 a nucleopliilic solvent such as methanol, cleavage of the imine linkage occurs to give difliioroamino compounds [78] (equation 12) W, At-Difluorotrifluoromethylamine can be prepared from or from thiocyanates, as shown in equation 13 [79, 80] Another way to produce difluoroamino compounds is the addition of fluorine to nitriles by means of AgFj [Sf ] or C0F3 [S/]... 

Peroxvaad oxidation of bridged 5,6,7,8-tetrafluoro 1 4-dihydronaphthalene-1,4 imines gives aromatic fluorohydrocarbons by elimination of the imine bridge [91] (equation 84) Almost the same yields are achieved by oxidation with 30% hydrogen peroxide m refluxing methanol [91]... 

A trifluoromethylsulfonamide can be prepared from a primary amine to allow monoalkylation of that amine. The triflamide is not stable to strong base, which causes elimination to an imine, but when used to protect an indole, it is cleaved with K2CO3 in refluxing methanol. ... 

Imine 24 was dissolved in sulfuric acid and the solution heated at 60 °C for 2h. The mixture was poured into cold water and the precipitate collected, washed with water and recrystallized from methanol to yield 25. 

Aminoquinoxaline 1-methiodide (65) is slowly formed when 2-aminoquinoxaline is treated with excess of methyl iodide in methanol at room temperature. Decomposition of the 1-methiodide with cold aqueous sodium hydroxide solution gives l-methylquinoxalin-2 one-imine (66) and this on hydrolysis yields l-methylquinoxalin-2-one. ... 

Bei a-Oxo-iminen wird in neutralem Milieu (Methanol/verd. Natronlauge/Bernstein-saure pH 7,15 geteilte Zelle) nur die Imin-Funktion reduziert6 ... 

A structurally related tetrameric macroheterocycle is compound 13 that is prepared in a one-pot synthesis (yield 64%) from salicylaldehyde and (3-aminophenyl)boronic acid in methanol (Fig. 4). Due to its insolubility it has been characterized only by mass spectrometry. If a substitutent is introduced at the imine function (R = Me, Ph), trimeric structures (14 and 15) are... 

Reductive activation of the quinone shown in Scheme 7.9 and incubation in methanol afforded a complex mixture of products consisting mainly of head-to-tail coupling at C-5 or C-7 (Scheme 7.10). Minor reactions involve transfer of H2 from the hydroquinone to the ene-imine (internal redox reaction) and methanol trapping. The structures of the dimers and trimers in Scheme 7.10 were derived from H-NMR,... 

Ugi and Domling have shown that the U-4CR can also be combined with other MCRs, thus creating sequences which involve up to nine different substrates [33]. An example of such an approach is the combination of an Ugi-4CR with the as-yet not mentioned Asinger reaction (A-3CR or A-4CR). The latter allows the formation of thiazolines from ammonia, carbonyl compounds and sulfides [34]. As shown in Scheme 9.7, a mixture of a-bromoisobutyraldehyde, isobutyraldehyde, sodium hy-drogensulfide and ammonia yields the imine 9-38 which, by reaction with t-butyl-isocyanide, methanol, and C02, led to the final product 9-39 [35]. 

Addition of A-mesityl benzimidazolyl carbene 720 to an a,/3-unsaturated aldehyde generates a homoenolate intermediate that undergoes an addition/acylation sequence with azomethine imine 719 to afford (3R, 5S, 6S )-177-pyrazolo[l,2- ]pyridazine-l,8(5//)-diones 721 with excellent diastereoselectivity. Compound 721 (Ar = R = Ph) treated with sodium hydoxide in methanol or benzylamine provided nearly quantitatively, ring-opened products 722a and 722b, respectively (Scheme 116) <2007JA5334>. 

Symmetric triblock copolymers of the ABA type, where B was PTHF and A poly(2-methyl-2-oxazoline), PMeOx, were prepared by cationic polymerization with trifluoromethanesulfonic anhydride as a difunctional initiator [58]. Subsequent hydrolysis of the PMeOx blocks with HC1 in a methanol/ water mixture resulted in the formation of the corresponding polyethylen-imine blocks (Scheme 20). Samples with relatively low molecular weight distributions were obtained. 

Nitrile ylids generated in this way can be trapped with methanol108 Thus, on irradiation in methanol, the azirine 137 was converted to the methoxy-imine (138). The intramolecular equivalent reaction leading to the oxazoline 139 has also been observed on irradiation of the 2//-azirine (140 R = OH),... 

Finally, a reaction should be mentioned in which a nucleophile gives support to another reacting species without appearing in the final product. Diphenyl cyclopropenone interacts with 2,6-dimethyl phenyl isocyanide only in the presence of tri-phenylphosphine with expansion of the three-ring to the imine 344 of cyclobutene-dione-1,2229,230 Addition of the isocyanide is preceded by formation of the ketene phosphorane 343, which can be isolated in pure formss 231 it is decomposed by methanol to triphenyl phosphine and the ester 52. 

Typically, the imine linkages can be reduced chemically (for example, using sodium borohydride in methanol), catalytically (for example, using H2 in the presence of a catalyst such as Pd/C) or electrochemically. The reduced ligands can normally be removed from their respective metal ions using one of a number of procedures. 

The cycloaddition of nitrile oxide 235 to the 4-iminobenzopyran-2-one 236 gave the fully conjugated 1,2,4-oxadiazole 238 directly, a reaction that most likely proceeds via loss of methanol from the intermediate 237 (Scheme 36) <1996JHC967>. Similarly, nitrile oxide 239 reacted with imine 240 to give the 1,2,4-oxadiazole 242 via the nonisolable intermediate 241 <2002PJC1137>. 

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