Acetylation laminate

In general, other properties of the acetylated laminates showed, improved properties over control laminates. For example, acetylated laminates in compression tests parallel to grain showed a 3% increase in stress at proportional limit, 8% increase in ultimate strength, 6% decrease in MOE, and 21% increase in deformation at failure as compared to controls. In compression tests perpendicular to the grain, acetylated laminates showed a 30% increase in stress at proportional limit, 47% increase in ultimate strength, 21% increase in MOE, and 10% increase in deformation at failure as compared to controls. 

Acetyl-AT-metbyl-o toluidine. Acetyl-AT-metbyl-m-toluidine. Acetyl-AT-methyl-p-toluidine. Acetyl-A7-methyl-a-napbthylamine Acety 1-AT-metbyl- P-naphthy lamine... 

Deprotect the acetylated —SH groups as needed by adding 100 pi of 0.5 M hydroxy-lamine hydrochloride in 50 mM sodium phosphate, 25 mM EDTA, pH 7.5, to each ml of the SATA-modified protein solution. 

C, and then three molecular equivalents of acetyl chloride and triethy-lamine were added. Three types of acetylated materials, 11, 12, and 13, were isolated accompanied by a small amount of thioketone 7 and thioamide 9 (Scheme 8 and Table 6). All of the acetylated materials showed optical activity. For the reaction of 6a, 84% ee of 2-(acetylthio)aziridine 11a, 50% ee of 4-(acetyl-thio)oxazoline 12a, and 20% ee of 4-(acetylthio)oxazolidin-2-one 13a were obtained in 39,10, and 16% yields, respectively. In the reaction of 6b,c, the corresponding optically active materials 11-13 were obtained as shown in Table 9. The formation of oxazoline 12 involves the rearrangement ofAT-acyl aziridines, which occurs by intramolecular attack of the carbonyl oxygen at the ring carbon to cause rupture of the system. 

In the hopes of accessing similar molecules that would contain C-6 functionalization, our group explored the cycloisomerization of such alkyne hemiketals as 152.70 Compound 152 was prepared by addition of ethynyltrimethylsilane to 5-0-terf-butyl-diphenylsilyl-2,3-0-isopropylidene-D-ribonolactone (151), followed by desilylation (25% over two steps). Trie thy lamine-mediated cycloisomerization71 provided an oxepinone, compound 153, in 41% yield. 1,2-Reduction of the enone functionality followed by acetylation under standard conditions provided 154 in 56% yield over two steps as a 3 1 ratio of diasteromers (the favored diastereomer is shown in Scheme 24). A small group of oxepines were prepared by this method. Variability in the yield of the cyclization step, which was moderate at best, has prevented this route from being applied more generally for the preparation of oxepines. 

Dinitrodcetylpbenylhydroxylamine, CbHtNj06, mw 241.16,N17.43%. One isomer, O-acetyl-N -(2,4-dinitropbenyl)-hydroxy lamine is described in Beil 15,[11]... 

Bis(trifluoromethyl)-4,5-dihydrooxazin-6-ones [28] and their O-acetylated derivatives [96] are formed on treatment of acyl imines with acetyl chlonde-triethy lamine at room temperature. The reaction was interpreted as a cycloaddition reaction involving a ketene [28] However, the penselectivity and regiochemistry of this reactwn-are not in agreement with results obtained from the reaction of... 

Acetyl-Af-methyl-1 -naphthy lamine 94 Ethylisopropylbarbituric acid 201... 

A direct approach to 3-aryl-2-chloro-4-iminothieno[2,3-d]pyrimidines 65a from A-aryl isocyanide dichlorides and o-aminocarbonitriles 48 was devised by Shishoo and Jain (92JHC883). 3-Aryl-4-imino-2-methylthieno [2,3-rf]pyrimidines 65b were obtained by heating a mixture of 2-acetyl-aminothiophene-3-carbonitriles 64a, phosphorus pentoxide, a primary ary-lamine hydrochloride, and /V,7V-dimethylcyclohexylamine hydrochloride in a molar ratio 1 6 4 4, at 160°C (88CS195 91EUP452002). Following similar reaction conditions but adding 8 parts of water to this reaction mixture... 

Catalytic transfer hydrogenation of nitrobenzene over 5% Rh-C in the presence of hydrazine is also effective in giving /V-phcnylhydroxylamine, which was isolated as the W-acetyl derivative in 79-80% yield although not very stable, A-phenylhydroxy-lamine could also be isolated in 75-85% yields (eq. 9.69).187... 

Selective trifluoroacetylation of primary amines in the presence of secondary amines can be accomplished by reaction with a stoichiometric amount of ethyl trifluoroacetate (bp 60-62 °C) in THF, acetonitrile or dioxane at 0 °C. The product is simply isolated by evaporation of the solvent and liberated ethanol,45-47 Perhaps the most common method entails acylation of the amine with trifluoro-acetic anhydride in the presence of a suitable base such as trie thy lamine or pyridine in dichloromethane [Scheme 8.26],40 New reagents for the N-trifluoro-acetylation of amines include Af-ftrifluoroacetyOsuccinimide,48 a solid and storable reagent, W-(trifluoroacetoxy)succinimide,49 which must be stored in a frozen benzene matrix, and l-(trifluoroacetyl)-l,2,3-benzotriazole.50 The latter reagent is a stable, crystalline reagent (mp 89-91 °C) prepared in quantitative... 

A second alkaloid without the oxazolidine ring, but with the carbino-lamine system is cycloneosamandaridine (XXVII). The IR-spectrum evidences a five-membered lactone ring (band at 1780 cm i) as well as the carbinolamine group (bands at 1050/1180 cm i). The IR-spectrum of the X-acetyl compound no longer shows these hands at 1050-1180 cm i, hut an additional carbonyl frequency at 1735 cm i for an aldehyde group. The mass spectrum confirms the molecular formula as well as structure XXVII(id). 

N-alkylated valine may be slmllarlly synthesized from an epoxide and valine. Figure 15A. Synthesis of DL-mlxtures of N-(2-hydroxyethyl)- and N-(2-hydroxypropyl)-vallne have been performed using o-bromo-lsovalerlc acid and the appropriate alky lamine, Figure 15B (2 ). The reactions of propylene oxide and N-acetyl-cystelne methyl ester, valine methyl ester and N-benzoyl-hlstldlne methyl ester respectively were recently thoroughly Investigated and the stereochemistry discussed (257). 

Acetyl and Feruloyl Esters in Pectin. A colorimetric method for determining degrees of acetylation in pectins from various sources ( ), has been shown to be rapid and quite sensitive. Hydroxy-lamine is reactive toward both the methyl and acetyl esters in pectin, and ferric ion complexes with the resulting hydroxamic acids are red. The pectin complex is insoluble and removed by filtration the intensity at 520nm in the soluble fraction, consisting of the ferric complex with acetohydroxamic acid, is a measure of acetyl content. The accuracy of the method was demonstrated in determinations of 0-acetyl levels in standard per-ace-tylated polysaccharides. Another method ( ) involves alkaline hydrolysis of the acetyl groups from pectin, followed by distillation of acetic acid and its titration with standard base. 

Spreux-Varoquaux, O. Chapalain, J.P. Cordonnier, P. Advenier, C. Pays, M. Lamine, L. Determination of trimethoprim, sulfamethoxazole emd its N4-acetyl metabohte in biological fluids by high-performance Uquid chromatography. J.Chromatogr., 1983, 274, 187—199... 

Aromatic amines are initially metabolized by aromatic and A-hydroxylation (oxidation reactions) and A-acetylation. Following aromatic ring hydroxylation, the ring structure may be further conjugated with glucuronic acid or sulfate (Parkinson 1996). N-hydroxylation results in the potential methemoglobin-generating metabolite, pheny Ihydroxy lamine. 

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