Pyridine-2-carboxylic acid phenyl ester

Chemical Name 2-[ [3-(Trifluoromethyl)phenyl] amino]-3-pyridine carboxylic acid 1,3-di-hydro-3-0X0-1 -isobenzofuranyl ester... 

Methyl-6-oxo-4-phenyl-l,4,5,6-tetrahydro-pyridine-3-carboxylic acid ethyl ester... 

At room temperature, 120 mg CuCN (1.3 mmol) was added to a stirred solution of 150 mg (3/ )-6-bromo-7-naphthalen-l-ylmethyl-5-oxo-8-phenyl-2,3-dihydro-57/-thiazolo[3,2-Q ]pyridine-3-carboxylic acid methyl ester (0.30 mmol) in 1.0 mL NMR The mixture was heated at 220°C for 20 min under microwave irradiation, and the solvent was then removed by lyophilization from deionized water. The residue was thoroughly extracted with CH2CI2, dried, and concentrated. Silica gel column chromatography using heptane/EtOAc (1 1) as the eluent afforded 110 mg (3R)-6-cyano-7-naphthalen-l-ylmethyl-5-oxo-8-phenyl-2,3-dihydro-5i/-thiazolo[3,2-o ]pyridine-3-carboxylic acid methyl ester as a white foam, in a yield of 82%. 

AUTONOM 6-Acetyl-3-(2-(3-lttert -butyl-phenyl)-ethylidene)-l-(2-fluoro-2-phenyl-thyl)-5-(8-nethyl-octahydro 2,5-nethano-isoqui olin-3-yl)-7 thioacryloyloxy-2, dihydro-l H pyrrolo[3,2 ltb ]pyridine-2 carboxylic acid vinyl ester... 

In the course of this study, the authors determined /Lvalues for dibenzyl, methyl phenyl, methyl p-nitrophenyl, di-p-tolyl, di-isopropyl and tetramethylene sulphoxides and for diethyl, dipropyl and dibutyl sulphites. The /Lscales are applied to the various reactions or the spectral measurements. The /Lscales have been divided into either family-dependent (FD) types, which means two or more compounds can share the same /Lscale, family-independent (FI) types. Consequently, a variety of /Lscales are now available for various families of the bases, including 29 aldehydes and ketones, 17 carboxylic amides and ureas, 14 carboxylic acids esters, 4 acyl halides, 5 nitriles, 10 ethers, 16 phosphine oxides, 12 sulphinyl compounds, 15 pyridines and pyrimidines, 16 sp3 hybridized amines and 10 alcohols. The enthalpies of formation of the hydrogen bond of 4-fluorophenol with both sulphoxides and phosphine oxides and related derivatives fit the empirical equation 18, where the standard deviation is y = 0.983. Several averaged scales are shown in Table 1588. 

Chloroformamidinium chlorides (29) are generated from DMF and oxalyl chloride in acetonitrile. After addition of the carboxylic acid the activated ester (26f) is formed and treated with a solution of the alcohol in pyridine. Phenyl, alkyl and even r-butyl esters may be prepared in yields of greater than 80% (equation 11). Reagent (31), accessible from (30) and oxalyl chloride (equation 12) behaves quite similarly to (29). The use of silyl esters (26g), which are formed in situ in Ae presence of the alcohol and react then to the esters, has already been mentioned in Section 2.2.1.2.1. An application is described in Table 1. 

Reactives of Side-Chains of Monocyclic Thiophens. - The rate constants for the esterification of some 3-, 4-, and 5-substituted thiophen-2-carboxylic acids and of some 2- and 4-substituted thiophen-3-carboxylic acids with diazodiphenylmethane in methanol solution have been measured, and linear correlations gave information about the transmission of substituent effects. The rates of alkaline hydrolysis of ethyl thiophen-2-carboxylate in ethanol-water and DMSO-water media have been measured and compared with those of other heterocyclic esters. The kinetics of iodination of 2-acetylthiophen in methanol-water, using different carboxylate buffers, have been studied.Basicity constants have been measured for j3-(2-thienyl)-acrylamides and compared with those of the corresponding benzene and furan derivatives. The acidity constants of ( )-a-phenyl-j3-(2-thienyl)-acrylic acids and analogous furan-, selenophen-, and pyridine-substituted compounds have been measured, and have been rationalized by an equation involving separate contributions of polar, conjugative, and steric effects of the heterocycles. ... 

Like the silyl ethers, the stability of the silyl esters parallels the steric bulk of the substituents on the silicon atom. Tris(2,6-diphenylbenzyl)siiy1 esters confer extraordinary steric protection upon the carboxyl group.234 For example, the tris(2,6-diphenylbenzyl)silyl ester of 4-phenylbutanoic acid 104.1 [Scheme 6.104] does not react with butyllithium (2.5 equiv) after 5 h at -78 °C or methylmag-nesium bromide (2,5 equiv) at room temperature. Nor did it react with lithium aluminium hydride after 30 min at 0 °C l M HC1 in THF at 40 °C, or aqueous sodium hydroxide at 50 °C after 5 h. Ester 104.1 was reduced with diisobutyl-aluminium hydride in 99% yield to give the 4-phenyl-l-butanol (99%) and HF pyridine in THF (1 2) at 50 aC cleaved it back to the acid after 5 h. Unfortunately, the penalty for such unusual stability is high the tris(2 6-diphenyl-... 

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