Pyridine-2,3 -dicarboxylic acid reaction with

Heating pyridine-2,3-dicarboxylic acid anhydride with l-ethyl-2-methylindole has been claimed to yield solely the pyridine-2-carboxylic acid, albeit in low yield. This then clearly reacts with Af,A/-diethyl-3-toluidine in acetic anhydride to give the 7-azaphthalide. This is surprising in view of a later report70 in which a one-pot process has been described. Heating pyridine-2,3-dicarboxylic anhydride, prepared in situ, with the indole and subsequent reaction with 3-/V,/V-diethylamino-phenetol under identical conditions to those used in Scheme 8 (but without intermediate isolations) produced a 20 1 mixture of the 4- and 7-azaisomers 16 and 17. It appears that in the previous report the major intermediate isomer, the pyridine-3-carboxylic acid, has not been isolated. 

AND ITS LARGER OCTALACTAM ANALOGUE 26, WHEN THE REACTION SEQUENCE SHOWN IN SCHEME 8 IS REVERSED AND EXTENDED DIAMINE 25 IS REACTED WITH 2,6-PYRIDINE DICARBOXYLIC ACID DICHLORIDE. 

A molecule with an even more spectacular topology was obtained when extended diamine 13 was reacted with 2,6-pyridine dicarboxylic acid dichloride. This was just a reversal of the order of the reaction steps in Figure 3. As well as the expected tetralactam macrocycle, its larger analogue octalactam wheel and a knot were formed [15], It was very surprising that a knot which bears three crossing points in its molecular... 

A typical member (la) of this group of chiral C2-symmetrical ligands is prepared by reaction of pyridine-2,6-dicarboxylic acid chloride with L-valinol (60% yield). 

Los, M., Ladner, D. W., Cross, B. (2-lmidazolin-2-yl)thieno- and -furo[2,3-b]pyridines and Use of Said Compounds as Herbicidal Agents, U.S. Patent 4,752,323, 1988. Ciba-Geigy, 2-lmidazolinyl-pyridine-and -quinolinecarboxylic Acid Production by Reaction of Pyridine or Quinoline-2,3-dicarboxylic Acid Esters with a 2-Amino-alkanoic Acid Amide, EP 233-150A, 1986. 

The ready decarboxylation of pyridine-carboxylic acids was also early appreciated. Historically, the reaction played an important role in the orientation of quinoline, isoquinoline and the benzoquinolines . Decarboxylation occurs more readily than with benzene-carboxylic acids, and in the sequence 2 > 4 > 3 (see p. 367). The decarboxylation temperatures of solid pyridine-dicarboxylic acids depend roughly on their strengths as acids— the stronger the acid the lower the temperature . At 185 -190 , pyridine-2,3,4-tricarboxylic acid gives pyridine-3,4-dicarboxylic acid, which above... 

Derivatives of some pyridine-dicarboxylic acids are of interest and value. Quinolinic acid anhydride gives, with ammonia, 2-aminocarbonylnicotinic acidi , which in the Hofinann reaction yields 2-aminonicotinic acid. Similarly, cinchomeronic anhydride gives 4-aminocarbonylnicotinic acid and thence 4-aminonicotinic acid . Use of quinolinic imide in the Hofinann reaction produces mainly 3-aminopicolinic acid and cinchomeronic imide gives 3-amino-isonicotinic acid whilst diamides of... 

This reaction consists of the condensation of two molecular equivalents of a 1,3 diketone (or a J3-keto-ester) with one equivalent of an aldehyde and one of ammonia. Thus the interaction of ethyl acetoacetate and acetaldehyde and ammonia affords the 1,4-dihy dro-pyridine derivative (1), which when boiled with dilute nitric acid readily undergoes dehydrogenation and aromatisation" to gb e the diethyl ester of collidine (or 2,4,6-trimethyl-pyridine-3,5 dicarboxylic acid (II)). For the initial condensation the solid aldehyde-ammonia can conveniently be used in place of the separate reagents. 

Mixed cellulose esters containing the dicarboxylate moiety, eg, cellulose acetate phthalate, have commercially useful properties such as alkaline solubihty and excellent film-forming characteristics. These esters can be prepared by the reaction of hydrolyzed cellulose acetate with a dicarboxyhc anhydride in a pyridine or, preferably, an acetic acid solvent with sodium acetate catalyst. Cellulose acetate phthalate [9004-38-0] for pharmaceutical and photographic uses is produced commercially via the acetic acid—sodium acetate method. 

The most common reaction of this type is the cyclization of various derivatives of hydrazine and substituted hydrazines with pyridine o-dicarboxylic acids and related compounds. Reactions in which the acid derivative reacts directly with the hydrazine are dealt with as [4 + 2] reactions in Section 2.15.10.6.1. 

In spirooxaziridines like (114), /3-scission proceeds with ring opening. Stoichiometric amounts of iron(II) salt in acidic solution lead to the dicarboxylic acid derivative (115). The radical undergoes some interesting reactions with added unsaturated compounds. For example, pyridine yields a mixture of 2- and 4-alkylation products in 80% yield. Catalytic amounts of iron(II) ion are sufficient here since the adduct of the radical with pyridine is oxidized by iron(III) ion to the final product (116), thus regenerating iron(II) ion (68TL5609). 

Sulfur compounds have also been widely studied as activating agents for polyesterification reactions. p-Toluenesulfonyl chloride (tosyl chloride) reacts with DMF in pyridine to form a Vilsmeir adduct which easily reacts with carboxylic acids at 100-120° C, giving highly reactive mixed carboxylic-sulfonic anhydrides.312 The reaction is efficient both for aromatic dicarboxylic acid-bisphenol312 and hydroxybenzoic acid314 polyesterifications (Scheme 2.31). The formation of phenyl tosylates as significant side products of this reaction has been reported.315... 

The scope of this reaction is similar to that of 10-21. Though anhydrides are somewhat less reactive than acyl halides, they are often used to prepare carboxylic esters. Acids, Lewis acids, and bases are often used as catalysts—most often, pyridine. Catalysis by pyridine is of the nucleophilic type (see 10-9). 4-(A,A-Dimethylamino)pyridine is a better catalyst than pyridine and can be used in cases where pyridine fails. " Nonbasic catalysts are cobalt(II) chloride " and TaCls—Si02. " Formic anhydride is not a stable compound but esters of formic acid can be prepared by treating alcohols " or phenols " with acetic-formic anhydride. Cyclic anhydrides give monoesterified dicarboxylic acids, for example,... 

High density brine completion fluids also often require the use of corrosion inhibitors (8,9). Blends of thioglycolates and thiourea alkyl, alkenyl, or alkynyl phosphonium salts thiocyanate salts mercaptoacetic acid and its salts and the reaction products of pyridine or pyrazine derivatives with dicarboxylic acid monoanhydrides have been used as high density brine corrosion inhibitors. 

PLLA-fr-PCL) multiblock copolymers were prepared from the coupling reaction between the bischloroformates of carboxylated PLLA with diol-terminated PCL in the presence of pyridine [140]. LLA was polymerized with SnOCt2 and 1,6-hexanediol followed by the reaction with succinic anhydride to provide the dicarboxylated PLLA. The carboxyl end groups were subsequently transformed to acid chloride groups by the reaction with thionyl chloride (Scheme 65). As expected, the molecular weight distributions were broad for all samples (1.84 < Mw/Mn < 3.17). 

Reaction of the m-nitrophenyl ester of pyridine-2,5-dicarboxylic acid with cyclodextrin (see Section 3) gives a picolinate ester [52] of a cyclodextrin secondary hydroxyl group (Breslow, 1971 Breslow and Overman, 1970) which will bind metal ions or a metal ion-pyridine carboxaldoxime complex. Such a complex will catalyse hydrolysis of p-nitrophenyl acetate bound within the cyclodextrin cavity leading to a rate constant approximately 2000-fold greater at... 

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