Pyridine, 4-butyl- , amination

VOH cm CO Aceto nitrile n-C4Hg C2H4 C3H6 /-C4H8 C4H6 Acetonitrile Pyridine NH3 n-Butyl amine Piperidine... 

The use of probe molecules that will sorb on specific acid sites has also been used to differentiate Brpnsted and Lewis sites. Studies on H-ZSM-5 and H-ZSM-8 suggest that pyridine cannot access the Lewis sites and thus essentially measures Brpnsted acidity 2,6-Dimethylpyridine has been reported to sorb preferentially on the Brpnsted sites of a variety of zeolites. Various amines have also been used to measure surface acidity. Since amines are weaker bases than either ammonia or pyridine, they preferentially sorb on the stronger acid sites. Both n-butyl amine and t-butyl amine have been used as adsorbates in TPD studies of zeolites. Comparison of the TPD spectra with butene isomerization has shown that butyl amines measure only the strong acid sites. 

A profitable way to quantitate the Lewis acid sites is to study the adsorbed molecules directly. For instance. Fig. 11 shows the C NMR results for butyl-amine adsorbates on 7-alumina [62]. In the adsorbate, there are two distinct resonances each for the a- and the P-carbon atoms of butylamines. Based on the model complex spectra included in Fig. 11, these peaks can be assigned to molecules bound to Bronsted and Lewis acid sites, respectively. In a similar fashion, C [63] and especially N CPMAS NMR studies of pyridine adsorbates on 7-alumina are able to differentiate among physisorbed molecules (64... 

First of all toluene is treated with chlorosulfonic acid to yield/ -toluenesulphonyl chloride, which on treatment with ammonia gives rise to the formation of/ -toluenesulphonamide. The resulting product on condensation with ethyl chloroformate in the presence of pyridine produces N-p-toluenesulphonyl carbamate with the loss of a mole of HCl. Further aminolysis of this product with butyl amine using ethylene glycol monomethyl ether as a reaction medium loses a mole of ethanol and yields tolbutamide. 

Specific area for pyridine of 29 it can be estimated that the amount of surface covered by the pyridine is 11 m /g-l or 5% of a monolayer. Similar coverages exist for the n-butyl amine. Operating under a dry nitrogen atmosphere the granular sample was packed into an aluminum oxide NMR rotor. 

The present design of our MAS probe is clearly amenable to variable temperature operation. Hence, one can study site exchange processes as a function of temperature and possibly separate rotational motion from translational motion of the molecule on the surface. Anisotropic rotational motion can be studied by nmr, e.g. deuterated pyridine and n-butyl amine. The ease of the experiment suggested that nmr with enriched samples would be equally as straightforward. In the near future, the Al, Ag, Rh nmr spectroscopy of the surface acceptor can also be studied. 

Catalysts acetonitrile Pyridine NH3 n-butyl amine Piperidine... 

Weak signals (ca. 10 M radicals/mole of Ss) are observed in n-butyl amine, n-heptylamine, ethanolamine, and morpholine. No signals are detectable for sulfur in triethylamine, aniline, pyridine, and diethylamine. 

All lation of Aromatic Amines and Pyridines. Commercially important aromatic amines are aniline [62-53-3] toluidine [26915-12-8], phenylenediamines [25265-76-3], and toluenediamines [25376-45-8] (see Amines, aromatic). The ortho alkylation of these aromatic amines with olefins, alcohols, and dienes to produce more valuable derivatives can be achieved with soHd acid catalysts. For instance, 5-/ f2 butyl-2,4-toluenediamine (C H gN2), which is used for performance polymer appHcations, is produced at 85% selectivity and 84% 2,4-toluenediamine [95-80-7] (2,4-4L)A)... 

Conversion of aromatic amines to azides was studied by Scechter et al. <2002TL8421> and these studies lead to the recognition of a new approach to tetrazolo[l,5- ]pyridine. Thus, reaction of 2-aminopyridine 142 with butyl-lithium followed by treatment with azidotris(diethylamino)phosphonium bromide gave rise to tetrazolo[l,5- ]pyr-idine 1 in 80% yield. The first intermediate is obviously the azide 7. 

FIGURE 8.15 Alkylamines encountered in peptide synthesis. 1, pyridine 2, 2,4,6-trimethylpy-ridine 3, 2,6-di-ferf-butyl-4-methylpyridine 4, 4-dimethylaminopyridine 5, A-methyl-morpholine, 6, fV-methylpiperidine 7, triethylamine 8, diisopropylethylamine 9, l-diethylaminopropane-2-ol 10, dicyclohexylamine 11, diethylamine 12, piperidine 13, piperazine 14, morpholine 15, l,8-diazabicyclo[5.4.0]undec-7-ene 16, 4-(aminoethyl)piperidine 17, frw(2-aminoethyl)amine 18, 3-dimethylaminopropylamine 19, methylamine 20, dimethy-laminoethane-2-ol 21, 1,2,2,6,6-pentamethylpiperidine 22, l,4-diazabicyclo[2,2,2]octane 23, 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5 -ene. 

The sterically hindered base 2,6-bis(tert-butyl)pyridine does not inhibit cyclization triaryl-amine retards this reaction photosensibilized one-electron oxidation of a diene leads to the same products, which are formed in the presence of ammoniumyl salt. As shown, in majority of cases, only the cation-radical chain mechanism of the diene-diene cyclization is feasible (Bauld et al. 1987). Meanwhile, cyclodimerizations of 2,4-dimethylpenta-l,3-diene (Gassman and Singleton 1984) and l,4-dimethylcyclohexa-l,3- or -1,4-diene (Davies et al. 1985) proceed through both mechanisms. 

In the presence of diisopropyl(ethyl)amine, tetrachlorosilane reacts with f-butyl hydroperoxide to give 1 1 adduct 9 (equation 16). Alkylperoxydiorganoalkoxysilanes are prepared from the reaction of chlorodiorganooxysilane with alkyl hydroperoxides in the presence of ammonia or organic base such as pyridine or triethylamine (equations 17 and 18). 

The results of some of the many aminations of pyridine and its derivatives that have been carried out appear in Table 14. Yields are quoted where possible but these should not be used for quantitative comparisons as reaction and work up conditions vary widely. 2-Alkylpyridines aminate at the vacant a-position, except when the substituent is very large. 2-f-Butylpyridine does not undergo the Chichibabin reaction, probably because the bulky 2-f-butyl group prevents adsorption on to the sodamide surface. In contrast, 2-phenylpyridine undergoes amination in very good yield. Aminations of 2- and 4-methyl-pyridines do not involve attack on the anhydrobases in aprotic solvents, but some ionization does take place in liquid ammonia. 4-Benzylpyridine forms a carbanion (148) which is only aminated with difficulty by a second mole of sodamide (equation 103). 

Enamines or imines can form pyridines by cyclization to a nitrile group, as shown in the production of compound (48). Alternatively, the nitrogen atpm of the nitrile can be made more nucleophilic by attack on the carbon atom by an external nucleophile. Ammonia causes cyclization of the dienamines (53) (77JHC1077) and (54) (78JAP(K)786878l) in both cases, elimination of the amine introduces the extra double bond. Dimethylamine or piperidine cause cyclization of l-cyano-2,5,5-trimethylhex-l-en-3-yne to the f-butyl-pyridine (55). There are a few other examples of the synthesis of bicyclic compounds from... 

Reaction of 4-chloro-6-fluoropyrido[3,4- pyrimidine 59 with [3-methyl-4-(pyridin-3-yloxy)phenyl]amine 60, followed by coupling the formed amine 61 with (3-azabicyclo[3.1.0]hex-6-yl)carbamic acid fi r7-butyl ester, afforded the substituted derivative 62 <2002EPP1249451>. Compound 59 was also reacted with 3-bromoaniline to give the 4-anilino derivative 63 that upon treatment with either methyl- or dimethylamine gave the corresponding 4,6-diamino derivatives 64 (Scheme 2) <1997W09726259, 1995W09519774>. 

Amines, pyridines and esters resist Jones oxidation, including the very acid-sensitive /-butyl esters.56 Amines and pyridines withstand Jones oxidation, probably because they are protected by protonation under the reaction conditions. 

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