Pyridine-2-acetic acid methyl ester

Other simple chelate ligands which have been found to give six-coordinate complexes NiX2L2 are 2-acetylpyridine N-oxide oxime,2495 2-acetamidopyridine,2496 pyridine-2-(acetic acid methyl ester)2497 and -substituted 2-aminopyridine N-oxides.2498... 

CN (5 )-.a-(2-Chlorophenyi)-6,7-dihydrothieno[3,2-c]pyridine-5(4//)-acetic acid methyl ester sulfate (1 1)... 

A method involving SPE was developed for the determination of ten A-nitroso amino acids in cured meat products. These compounds were derivatized with diazomethane followed by O-acylation of hydroxyl groups with acetic anhydride-pyridine reagent. The methyl esters and their acylated derivatives were separated by GC on a DB-5 fused silica capillary column and quantified with a TEA-CLD specific for the nitric oxide derived from the thermal denitrosation of nitrosamines recovery exceeded 75% at the 10 ppb level579. 

A solution of 460 mg of (+/-)-2a-(2-carboxy-2-formylethyl)-3p-hydroxy-5-oxo-ip-cyclopentaneheptanoic acid methyl ester 6-lactone, 5-cyclic ethylene acetal in 6 ml of methylene chloride and 4.4 ml of pyridine was treated with a 5% ozone-oxygen mixture at - 70°C until the mixture had persistent pale blue color. The excess of ozone was evaporated by bubbling nitrogen into reaction and the solvents were removed in vacuo. The residue was tirturaed with ether affording crystalline (+/-)-2a-(2-carboxy-2-oxoethyl)-3p-hydroxy-5-oxo-ip-cyclopentaneheptanoic acid methyl ester 6-lactone, 5-cyclic ethylene acetal, m.p. 114-116°C. 

To a solution of the S-(+)-4-acethoxy-9-[2-(5-ethyl-l,2,3,6-tetrahydro-pyridin-3yl)-l-(lH-indol-2-yl)-l-methoxycarbonyl-ethyl]-3a-ethyl-5-hydroxy-8-methoxy-6-methyl-3a,4,5,5a,6,ll,12,12b-octahydro-lH-6,12a-diaza-indeno[7,l-ca]fluorene-5-carboxylic acid methyl ester in dioxane and glacial acetic acid was added 37% aqueous formaldehyde and the mixture stirred at 35°C for 24 h. The solution was evaporated in vacuo and the residue suspended in chloroform and washed with cold aqueous 5% K2C03 solution. The chloroform layer was dried (MgS04), filtered, and evaporated. The residue was chromatographed eluting with EtOAc/MeOH, 10% NH4OH to give the product navelbine. 

Polymer-bound isonitrile (423), obtained from TentaGel-NH2 through treatment of the resin with formic acid and acetic anhydride, followed by dehydration of the resulting formamide with tosyl chloride and pyridine, has been employed in the preparation of N-substituted amino add ester [349]. Thus, Ugi MCR, performed in the presence of an alcohol instead of the carboxylic component, gave rise to an imino-ether spedes (426). Several Lewis acids were tested in searching for optimal reaction conditions. Boron trifluoride etherate displayed the better yields in term of desired product of the Ugi-type reaction. Amino acid methyl esters (427) were thus obtained when using methanol as the alcohol component, after deavage from the resin of the intermediate imino-ethers by an acetone/water mixture (Scheme 87). 

Synthesis and Reactions.- The o- and -penta-O-acetates (1) and (2), respectively, and the -tetra-Q-acetate (3) of N-acetylneuraminic acid methyl ester have been prepared in good to excellent yields by use of the reagents indicated in Scheme 1. Direct acetylation of methyl N-acetylneuraminate with acetic anhydride-pyridine gave a 1 3 mixture of the anomeric peracetates (1) and (2). The selective synthesis of mono- and di-O-acetates of an aryl glycoside of N-acetylneuraminic acid benzyl ester is covered in Chapter 16. 

Table 4. G.l.c. and m,s. data of acetylatedjmethylated N,N-acyl,methyl-neuraminic acid methyl ester -methyl glycosides. The Rf gj sAc alues on a packed column (2m x4 mm, i.d.) of 3.8% SE-30 on Chromosorb W-A W DMCS HP, 80-100 mesh at 220 °C (Van Halbeek et al. 1978) are given relative to Neu5Ac4,5,7,8,9Me methyl ester -methyl glycoside. The acetylation is carried out at 100°C for 30 min with acetic anhydride-pyridine...

An AB2-type monomer (1-13, Scheme 8), was synthesized by Yamanaka et al. [133] starting from 3,5-dimethoxyphenol via a polyamic acid methyl ester precursor. The aromatic hb-PIs were prepared by chemical imidization in the presence of acetic anhydride and pyridine. The synthesized polyimides were soluble in polar aprotic solvents and showed thermal stability, with a Tajo% of 470°C in nitrogen and a Tg of 193°C. In another work by Yamanaka et al. [134], the same AB2 monomer containing free amine end groups of the precursor was end-capped with acetyl, n-heptanoyl chloride, and 4-methylphthalic anhydride. By chemical imidization of these precursors in the presence of acetic anhydride and pyridine, hb-PIs were prepared. The DB of the hb-PIs was 50% as expected. The hb-PIs showed a above 395°C, and Tg values of 189, 138, and 186°C for the end groups of acetoamide, -heptanoamide, and 4-methylphthalimide, respectively. 

In methanol, isoquinoline and the ester gave the benzo[fif]indolizine [(121), cf. Section II,D,3] while in ether the labile adduct, tetra-methyl llbH-benzo[a]quinolizine-l,2,3,4-tetracarboxylate (122) was obtained. The labile adduct is much less easily isoraerized than the 9-methyl-9aH-quinolizines derived from pyridines (Section III,F,1) but with boiling xylene or, better, with sulfuric-acetic acids the cor-... 

The solvents most commonly employed are water, ethyl and methyl alcohol, ether, benzene, petroleum ether, acetone, glacial acetic acid also two or three solvents may be mixed to get the desired effect as described later. If you still cannot dissolve the compound, try some of these chloroform, carbon disulfide, carbon tetrachloride, ethyl acetate, pyridine, hydrochloric acid, sulfuric acid (acids are usually diluted first), nitrobenzene, aniline, phenol, dioxan, ethylene dichloride, di, tri, tetrachloroethylene, tetrachloroethane, dichloroethyl ether, cyclohexane, cyclohexanol, tetralin, decalin, triacetin, ethylene glycol and its esters and ethers, butyl alcohol, diacetone alcohol, ethyl lactate, isopropyl ether, etc. 

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