Carboxyethylation

Carboxy-3-(2-carboxyethyl)-7-chloro-2-(ethoxy carbonyl) 2-Ethoxycarbonylcyclopentanone BF3-HOAC 63,81 [1]... 

Compounds of type 184 were prepared similarly with R, = methyl and R2 = alkanoic esters (136, 229, 304) or carboxyethyl (4, 10, 13, 22, 220) (Table 11-27). Dichloroacetone reacts with ammonium thiocyanate, but... 

To the previous reaction we related the dehydration of ethyl-2-acetamido-2-thiocarbamoylacetate. This latter compound, heated in the presence of POCI3 20 min at 80°C and then 35 min at 95°C, gives 5-amino-4-carboxyethyl-2-methylthiazole in 77.5% yield. In a similar manner, 2-fonnaminothioacetaniide gives the 5-aminothiazole (718). 

Succineins. Succineins are carboxyethyl-substituted pyronines made by substituting succinic anhydride for formaldehyde in the basic synthesis,... 

Many of these reactions are reversible, and for the stronger nucleophiles they usually proceed the fastest. Typical examples are the addition of ammonia, amines, phosphines, and bisulfite. Alkaline conditions permit the addition of mercaptans, sulfides, ketones, nitroalkanes, and alcohols to acrylamide. Good examples of alcohol reactions are those involving polymeric alcohols such as poly(vinyl alcohol), cellulose, and starch. The alkaline conditions employed with these reactions result in partial hydrolysis of the amide, yielding mixed carbamojdethyl and carboxyethyl products. 

Reaction of olefin oxides (epoxides) to produce poly(oxyalkylene) ether derivatives is the etherification of polyols of greatest commercial importance. Epoxides used include ethylene oxide, propylene oxide, and epichl orohydrin. The products of oxyalkylation have the same number of hydroxyl groups per mole as the starting polyol. Examples include the poly(oxypropylene) ethers of sorbitol (130) and lactitol (131), usually formed in the presence of an alkaline catalyst such as potassium hydroxide. Reaction of epichl orohydrin and isosorbide leads to the bisglycidyl ether (132). A polysubstituted carboxyethyl ether of mannitol has been obtained by the interaction of mannitol with acrylonitrile followed by hydrolysis of the intermediate cyanoethyl ether (133). 

Total Synthesis. Poor yields encountered duriag the manufacture of vitamin D stimulated early attempts to synthesize vitamin D. In 1959 Inhoffen synthesized vitamin from 3-methyl-2-(2-carboxyethyl)-2-cyclohexenone (40), uskig the Wittig reaction extensively (103). 

Putidolumazine 6-(2-Carboxyethyl)-8-D-ribitylpteridine-2,4,7-trione 6-(L-l, 2 -Dihydroxyethyl)-8-D-ribitylpteridine-2,4,7- —... 

Dlmethyl-3-carboxyethyl-5 p-methoxyphenyl)-4,5 dlhydrofuran (3).3 A mixture of syn and anti cyclopropyl-p ketoesters 1 and 2 was left in contact with neutral akjmina activity I in CHCI3 for 24 h The starting materials 1 and 2 disappeared and 3, homogeneous by HPLC and NMR in quantitative yield, was isolated... 

V-Acetyl muramic acid [NAMA, R-2-(acetylamino)-3-0-(l-carboxyethyl)-2-deoxy-D-glucose] [10597-89-4] M 292.3, m -125°(dec),... 

Trimethylsilylethynylpyrazole was deprotected by treatment with tetrabutyl-ammonium fluoride (TBAF) to give monosubstituted acetylene in 90% yield. (96ADD193). The same conditions were used to cleave the trimethylsilyl group in l-tetrahydropyranyl-3-carboxyethyl-4-[2-(trimethylsilyl)ethynyl]pyrazole (96INP 9640704). 

Treatment of pyrimidine-2-thione 193 with AICI3 in PhN02 yielded 2-(4-benzylphenyl)-6-oxo-6,7-dihydro-4//-pyrido[6,l-a]isoquinolin-4-thione (194) (98MI47). Cyclization of l-(2-carboxyethyl)-l,2,3,4-tetrahydroquina-zoline-2,4-dione (195) in PPA afforded l,2,3,5,6,7-hexahydropyrimido[3,2, l-//]quinazoline-l,3,7-trione (196) (97CHE96). 

Condensation with the ylide from diethyl (carboxyethyl)-phosphonate gives the corresponding ester largely as the E isomer. The epoxide is then opened with acetate (117) and... 

Propiolactone is subject to attack by enolate ions to give propionic acid derivatives of ketones. It may likewise react with nucleophilic enamines to give carboxyethylation according to the reactions. The morpholide is easily hydrolyzed to the corresponding acid. 

The lactone is prepared as follows A solution of 5 parts of 17a-carboxyethyl-17/3-hydroxy-androst-4-en-3-one lactone and 5 parts of chloranil in 400 parts of xylene containing a trace of p-toluenesulfonic acid is heated at the boiling point of the solvent under reflux overnight. The solution is then cooled and filtered through approximately 200 parts of silica gel. The gel is successively washed with 5%, 10%, and 15% ethyl acetate-benzene... 

A mixture of approximately 11 parts of 17o-(2-carboxyethyl)-17(3-hydroxyandrosta-4,6-dien-3-one lactone and 10 parts of thioacetic acid is heated at 85° to 95°C for h hour. Excess thioacetic acid is removed by vacuum distillation at this point, and the residue is twice recrystallized from methanol, affording 7o-acetylthio-17o-(2-carboxyethyl)-17(3-hy-droxyandrost-4-en-3-one lactone, melting at approximately 134° to 135°C. Heated above this melting point, the product solidifies and melts again at approximately 201° to 202°C (with decomposition). 

Alpert has shown [47] that poly(succinimide)-silica can be further hydrolyzed to poly (aspartic acid)-silica or condensed with [3-alanine in aqueous solution to form a covalently bonded copolymer of 2-carboxyethyl aspartamide and aspartic acid. The content of carboxyl groups generated by this way has not been quantified directly, but the cation-exchange hemoglobin capacity has been measured for a series of the packings. Thus, the optimal concentration of poly(succinimide) used in the synthesis was found to be 2 5%. 

Phosphine, amino-rhodium complexes catalysts, hydroformylation, 6,261 Phosphine, 3-aminopropyldimethyl-photographic fixer, 6,100 Phosphine, bis(2-carboxyethyl)methyl-photography... 

The dianion of 2-carboxyethyl phenyl sulphoxide 362 undergoes alkylation at the a-position to the sulphinyl group440,441 (equation 205). 

Longer carbon chains can also be added, such as carboxyethyl groups, or carboxypropyl groups. Adding bulky functional components like carboxymethyl and carboxyethyl groups reduces the tendency of the starch to recrystallize. When the starch stays as a gel, a product is softer, and we refer to it as fresh. When the starch regains its crystalline form, the product becomes firmer, and we refer to it as stale. The technical term for this recrystallization is starch retrogradation. 

Gerhardt et al. [34] described three possible ways to prepare alkylphenol-polyglycol ether carboxylates, namely, the method with NaOH and SMCA, the method by oxidation by means of oxygen, and the method whereby the nonionic reacts with acrylonitrile followed by hydrolyses with hydrochloric acid. The synthesis with acrylonitrile forms in contrast to the other two methods, carboxyethylated compounds with the general formula... 

In the presence of strong alkali dialkyl phosphites can be added to unsaturated compounds. Thus salts of carboxyethyl- or dicarboxyethylphosphonic acid are obtained by addition of dialkyl phosphites to methyl acrylate [99] in the presence of sodium methylate in methanol. Diethylmaleate similarly gave diethyldiethylphosphonosuccinate [100], according to Eqs. (55) and (56) ... 

Muramic acid for 2-amino-3-0-[(/ )-l-carboxyethyl]-2-deoxy-D-glucose. 

Amino-3-0-[(fl)-1-carboxyethyl]-2-deoxy-p-D-glucopyranose (p-muramic acid)... 

Carboxyethyl 1 -seleno-p-D-xylopyranoside or 3-(P-D-xylopyranosylseleno)propanoic acid... 

Se-p-D-Ribopyranosyl-D-selenocysteine or (S)-2-amino-2-carboxyethyl 1-seleno-p-D-ribopyranoside or 3-(P-D-ribopyranosylseleno)-D-alanine... 

Table 1.5 Ni(COD)2/PPh3 catalyzed /zo/wo-Diels-Alder reactions of 2-carboxyethyl-norbomadiene with electron-deficient dienophiles...

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