Carboxyl derivatives

Pentenamer Ionomers. Unsaturated polypentenamer elastomers have been derivatized by post-synthesis reactions (72—74). Phosphonate, thioglycolate, sulfonate, and carboxylate derivatives have been prepared and converted into ionomers. 

Catalytic oxidation ia the presence of metals is claimed as both nonspecific and specific for the 6-hydoxyl depending on the metals used and the conditions employed for the oxidation. Nonspecific oxidation is achieved with silver or copper and oxygen (243), and noble metals with bismuth and oxygen (244). Specific oxidation is claimed with platinum at pH 6—10 ia water ia the presence of oxygen (245). Related patents to water-soluble carboxylated derivatives of starch are Hoechst s on the oxidation of ethoxylated starch and another on the oxidation of sucrose to a tricarboxyhc acid. AH the oxidations are specific to primary hydroxyls and are with a platinum catalyst at pH near neutraUty ia the presence of oxygen (246,247). Polysaccharides as raw materials ia the detergent iadustry have been reviewed (248). 

In all cases, a higher percentage of hydroxylamino trapping occurs in the presence of mineral acid, and the hydroxylamino trapping abilities of the carboxy derivatives increase as R = OH < OMe < NH2. Thi.s order is reversed in the absence of mineral acid. Presumably the carboxyl derivative is protonated in the presence of acid and thus becomes a better electrophile. 

Treatment of alkyl 9-benzyloxycarbonyl-3-methyl-6-oxo-2/7,6//-pyr-ido[2,l-f ][l,3]thiazine-4-carboxylates with BBr3 in CH2CI2 at -70 °C for 0.5-1 h and at room temperature for 3h yielded 9-carboxyl derivatives. The decarboxylation of these acids was unsuccessful. Hydrolysis of diethyl cA-3,4-H-3,4-dihydro-3-methyl-6-oxo-2//,6//-pyrido[2,l-f ][l,3]thiazine-4,9-dicarboxylate in aqueous EtOH with KOH at room temperature for 3 days yielded 4-ethoxycarbonyl-3,4-dihydro-3-methyl-6-oxo-2//,6//-pyrido-[2,l-f ] [1,3]thiazine-9-carboxylic acid (00JCS(P1)4373). Alkyl 9-hydroxy-methyl-3-methyl-6-oxo-3,4-dihydro-2//,6//-pyrido[2,l-f ][l,3]thiazine-4-car-boxylates were O-acylated with AC2O and (PhC0)20 in pyridine at room temperature for 12-48h. 

The observation that a carboxyl derivative of a pyrimidinoquinol ine shows mediator release inhibiting activity is in consonance with the earlier generalization. Knoevenagel condensation of nitroaldehyde 138 with cyano-acetamide gives the product 139. Treatment with iron in... 

Yosida et al. [41] found that p-t< rr-butylcalix[6]ar-ene can extract Cu from the alkaline-ammonia solution to the organic solvent. Nagasaki and Shinkai [42] described the synthesis of carboxyl, derivatives of calix-[n]arenes ( = 4 and 6) and their selective extraction capacity of transition metal cations from aqueous phase to the organic phase. Gutsche and Nam [43] have synthesized various substituted calix[n]arenes and examined the complexes of the p-bromo benzene sulfonate of p-(2-aminoethyl)calix[4]arene with Ni, Cu , Co-, and Fe. ... 

The first clinical trials were performed in the 1970 s using a sodium salt derivative with an open E-ting (Fig. 1). However, the clinical efficacy was limited and severe bladder toxicity led to the termination of the clinical trials. The poor efficacy of the camptothecin sodium salt in those clinical trials was probably due to the fact that the open E-ring form of camptothecin (carboxylate derivative) is inactive as a Topi inhibitor. Following the identification of Topi as a target of camptothecin, water-soluble derivatives were produced by the pharmaceutical industry. Two of these water-soluble derivatives have been approved by the FDA for cancer treatment in the early 2000s topotecan and irinotecan. 

Various heterocyclic moieties have been incorporated at the glyphosate carboxylate center as potential "masked" carboxyl derivatives 62. All of those reported to date contain a fully unsaturated heteroaromatic ring. 

The c.d. spectra of a number of other derivatives have been measured as models for the linkages found in oligomers. Spectra of the methyl a-and )8-D-ketopyranosides of N-acetylneuraminic acid are given in Fig. 29. They do not differ substantially from the c.d. spectra for the fundamental sugars, except that the a-ketopyranoside has a positive c.d. band of low intensity at 250 nm. These types of bands occur from time to time for still obscure reasons, as discussed for carboxyl derivatives. 

Tinti and coworkers compared the sweetness of the derivatives of 2-propoxy-5-nitroanilines in which the nitro group was replaced by a CN or a CO J substituent. They found that the cyano derivative is sweet (although the sweetness is only one-third that of the nitro derivative), whereas the carboxyl derivative is not this seemed to suggest that the nitro group may not be the B unit of the AH,B system, as assigned by both Shallenberger... 

A carboxylate derivative of a fully aromatic, water-soluble, hyperbranched polyphenylene is considered as a unimolecular micelle due to its ability to complex and solubilize non-polar guest molecules [23]. The carboxylic acid derivative of hyperbranched polyphenylene polymer (HBP) (My,=5750-7077, Mn=3810-3910) consists of 40-60 phenyl units that branch outward from a central point forming a roughly spherical molecule with carboxylates on the outer surface. The free acid form of HBP was suspended in distilled water and dissolved by adding a minimum quantity of NaOH. The solution was adjusted to pH 6.2 with aqueous HCl. Calcium carbonate crystals were growth from supersaturated calcium hydrogencarbonate solution at room temperature. HBP gave... 

IR spectroscopy is often used for distinguishing between unidentate and bidentate coordination of carboxylate (02CR) ligands. For monomeric carboxylate derivatives the separation between the symmetric and asymmetric C02 stretching bands, At = [t asym(C02) - t syJCOa)], provides a useful indication of the coordination mode complexes which exhibit values of greater than 200 cm-1 invariably possess unidentate coordination. Deacon, G. B. Phillips, R. J. Coord. Chem. Rev. 1980, 33, 227. 

With N,0 mixed donor ligands several complexes have been reported with ligands such as 4,5-dichloro-2-cyano-3,6-dione-l,4-cyclohexen-l-ol,1445 isonicotinic acid,1446 p-aminobenzoic acid,1447 alanine, histidine or histamine derivatives,1448-1450 [N(0)C(CN)2]-,1451 pyridine-carboxylate derivatives, 1452 1454 [N(pph20)2] (263),1455 bis(sulfonyl)amide derivatives,1456,1457 tris(pyridyl)-... 

With regard to carboxylic derivatives, there is generally little difference in chemical shift among the various trifluoroacetic acid derivatives, as exemplified by the examples in Scheme 5.25. Also, the effect of moving the CF3 farther from the carboxylic acid function is similar... 

This is another reaction that involves carbanions derived from esters, e.g. (Ill), but this time adding to the carbonyl carbon atom of another ester molecule. The reason for considering it here rather than under carboxylic derivatives (p. 237) is that it can, in its initiation, be regarded as something of an analogue, for esters, of the aldol condensation on aldehydes (cf. p. 224), e.g. with ethyl ethanoate (acetate, 112) ... 

ADDITION/ELIMIN ATION REACTIONS OF CARBOXYLIC DERIVATIVES... 

This adduct (=100% yield) may be isolated and characterised the less nucleophilic H20 or EtOH does not add on. On going from the original carboxylic derivative (156) to the tetrahedral intermediate... 

Ethyl 9,10-difluoro-3-methyl-7-oxo-7/7-[l,2,4]oxadiazino[6,5,4- /]quinoline-6-carboxylate 157 could be successfully hydrolyzed to the carboxylic derivative 158 by treatment with fuming sulfuric acid under cooling. In contrast, attempts using various other conditions (1 M HC1/THF or AcOH/HCl or M HCl/EtOH or 1% NaOH) did not afford 158 (Scheme 17). 

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