C-Carboxymethylation

Methyl 2,4-dideoxy-4-C-carboxymethyl-a-D-riZ o-hexopyranoside 2 -> 3 lactone (43), required as a key intermediate for the synthesis of optically active thromboxanes, has been synthesized from D-glucose by standard transformations. ... 

Fig. 5 Chemical stractme of a hydroxypropyl cellulose, b hydroxypropyl methyl cellulose and c carboxymethyl cellulose...

Branched-chain Sugars. - 5-C-Methyl-a L-idopyranose, 6-deoxy-7-C-(2-furyl)-l,2 3,4-di-0-isopropylidene-L-gtycero-a-D-galacto-htptopyranose, tert-butyl 4-C-aminomethyl 3-C-carboxymethyl-2,3,4-trideoxy-a-D-fyxo-hexopyranoside-5-lactam, the 3-C-substituted 3-deoxy-a-D-altroside (20), methyl 4,6-0-benzylidene-2-0-(4-bromobenzoyl)-3-C-(3-methyl-... 

Other Alkyl and Aryl Ethers. - The preparation of selectively 0-alkylated saccharides, including benzyl, allyl, triphenylmethyl, and arylalkyl ethers has been reviewed. Analogues of lipids A and X incorporating 3-O-alkyl (rather than acyl) linkages have been described, and some carbohydrate monoalcohol derivatives have been alkylated with haloacetic acid ester derivatives. ° 3-C -Carboxymethyl D-glucose and D-fhictose compounds have been coupled via the carboxylic acid group to L-lysine in a search for acrosin inhibitors."... 

Sodium azide does not react with carbonyl sulfide to form 5-hydroxy-1,2,3,4-thiatriazole, nor with carboxymethyl xanthates, RO-CS SCH2COOH, to form 5-alkoxy-l,2,3,4-thiatriazoles. The latter, however, could be prepared from xanthogenhydrazides (RO-CS NHNH2) and nitrous acid. They are very unstable and may decompose explosively at room temperature only the ethoxy compound (6) has been examined in detail. This is a solid which decomposes rapidly at room temperature and even at 0°C is transformed after some months into a mixture of sulfur and triethyl isocyanurate. In ethereal solution at 20° C the decomposition takes place according to Eq. (16)... 

Thereby the S-carboxymethyl-L-cysteine precipitates out in crystalline form. The product is filtered off with suction, well stirred in 500 ml of water, again filtered with suction and dried in a vacuum at 70°C. The yield is 92% based on L-cysteine. 

Therefore a special N-containing ether carboxylate was developed [36] with a high melting point ( 90°C) with a good foam and low hard water sensibility. This is obtained by condensation of a fatty acid (e.g., lauric acid) with diglycolamine, followed by carboxymethylation with NaOH and SMCA, washing out of the reaction mixture with a aqueous solution of a strong acid, separation of the oil layer, and neutralization with NaOH or KOH. The result is an ether carboxylate with exactly 2 EO units with the structure ... 

Surfactants are prepared which contain carboxylic acid ester or amide chains and terminal acid groups selected from phosphoric acid, carboxymethyl, sulfuric acid, sulfonic acid, and phosphonic acid. These surfactants can be obtained by reaction of phosphoric acid or phosphorus pentoxide with polyhydroxystearic acid or polycaprolactone at 180-190°C under an inert gas. They are useful as polymerization catalysts and as dispersing agents for fuel, diesel, and paraffin oils [69]. 

Benzenesulfonyl-l-ethoxycarbonylmethyl-3,4-dihydro-2(l//)-quinoxalinone (8) gave either l-carboxymethyl-2(l//)-quinoxalinone (9) (1.25M NaOH, reflux, 6 h 92% note additional nuclear oxidation by loss of PhS02H) or 4-benzenesulfonyl-1 -carboxymethyl-3,4-dihydro-2(lfl)-quinoxalinone (10) (H2 SO4, AcOH, H2O, 80°C, 15 min then 60°C, 5 h then 20°C, 16 h 27%). Methyl 3-methyl-2-quinoxalinecarboxylate 1,4-dioxide (11, R = Me) gave 3-methyl-2-quinoxalinecarboxyhc acid 1,4-dioxide (11, R = H) (Et3N, CaCl2,... 

Benzoyl-l-benzyloxycarbonylmethyl-3,4-dihydro-2(17i)-quinoxalinone (14) gave l-carboxymethyl-3,4-dihydro-2(l//)-quinoxalinone (15) (Pd/C, AcOEt, H2, 20°C, 90% note additional A-debenzoylation)." ... 

Y. T. Kalashnikov. Lubricant-sealer for profiled joints of casing pipes— contains soap plastic lubricant, polyacrylamide or carboxymethyl cellulose and additionally gypsum or cement powder, to increase sealing rate. Patent RU 2007438-C, 1994. 

V. G. Mosienko, Y. I. Petrakov, A. M. Pedus, and V. N. Nikiforova. Complex additive to plugging solution—contains waste from production of sebacic acid, ammonium sulphate and carboxymethyl cellulose, reducing water separation, etc. Patent RU 2078908-C, 1997. 

V. M. Ryzhov, V. S. Mironyuk, T. Ya. Mazepa, and V. V. Muravev. Controlling water absorption of drilling solution— based on carboxymethyl cellulose, involves introduction of sodium and/or potassium chloride into aqueous solution of carboxymethyl cellulose. Patent RU 2066684-C, 1996. 

Berry, C.N., Lloyd, K.G. and Louisot, P. (1992). Effects of S-carboxymethyl-L-cysteine on pulmonary sialyl transferease activity in vitro, in healthy and in sulphur dioxide induced bronchitic rats. Fund. Clin. Pharmacol. 6, 29-35. 

Torres, A. R., Edberg, S.C., and Peterson, E. A., Preparative high-performance liquid chromatography of proteins on an anion exchanger using unfractionated carboxymethyl displacers, /. Chromatogr., 389, 177, 1987. 

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