Sodium bromoacetate

The oxocarbenium perchlorate C(CH20CH2CH2C0+C104 )4 was employed as a tetrafunctional initiator for the synthesis of PTHF 4-arm stars [146]. The living ends were subsequently reacted either with sodium bromoacetate or bromoisobutyryl chloride. The end-capping reaction was not efficient in the first case (lower than 45%). Therefore, the second procedure was the method of choice for the synthesis of the bromoisobutyryl star-shaped macroinitiators. In the presence of CuCl/bpy the ATRP of styrene was initiated in bulk, leading to the formation of (PTHF-fc-PS)4 star-block copolymers. Further addition of MMA provided the (PTHF-fr-PS-fc-PMMA)4 star-block terpolymers. Relatively narrow molecular weight distributions were obtained with this synthetic procedure. 

The effects of several cationic and anionic surfactants on the nucleophilic aliphatic substitution reaction between thiosulfate ion and sodium bromoacetate (see Table 16) have been investigated by Erikson and Lingafelter (1955) and Sebba and Wiggill (1966). The reaction in the presence of anionic surfactants was influenced only slightly by micelliza-tion whereas dodecyltrimethylammonium bromide and CTAB accelerated the reaction by factors of 1-6 and 4-3 respectively. In the latter case the rate acceleration was found to be the consequence of a decrease in the energy of activation (Sebba and Wiggill, 1966). 

A solution contains bromoacetic acid, BrCH2COOH, and sodium bromoacetate, NaBrCH2COO, with a total concentration of 0.30 mol/L. If the pH is 3.10, what are the concentrations of the acid and the salt = 2.0 X 10 for BrCH2COOH. 

Af,Af -disubstituted 2/f-l,2,4-oxadiazin-3,5(4//,6//)-diones (e.g. (199)) can be synthesized by condensing sodium bromoacetate with an A -hydroxyurea (e.g. (197)), followed by cyclization of the resulting oxyacetic acid (198) with thionyl chloride in THF (Scheme 34) <89JAP(K)oi 186882>. Likewise, AT-aryl-AT -alkyl-Ar -hydroxyureas (200), prepared by the addition of an alkylhydroxylamine (RNHOH) to an aryl isocyanate (ArNCO), are precursors of 2-alkyl-4-aryl-5,6-dihydro-2 -1,2,4-oxadiazin-3(4//)-ones (201), the two carbon fragment in this instance being provided by 1,2-dichloroethane (Equation (15)) <91FRP2660158). 

Etherification of Sucrose Chelates by Allyl Halides, and Sodium Bromoacetate, Allyl bromide or chloride was added to a dimethylsulphoxide (DMSO) solution of sucrose chelate in the ratios of sucrose allyl halide 1 1,1, 1 1,3, 1 2,0 and 1 2,5 and kept at 80°C for 16 to 48 h. The allyl bromide reactions were carried out in screw cap, sealed test tubes and most of the allyl chloride reactions in a sealed autoclave. Decomposition of the sucrose was prevented by keeping the ratio of sucrose to allyl halide equal or less than the ratio 1 2,5. The reaction between sucrose chelates and sodium bromoacetate was performed in the following ratios sucrose bromoacetate, 1 2,6, 1 3,8, 1 5,2 and 1 7,0, in DMSO for 72 h at 70°C. 

Sucrose chelates in DMSO react selectively with allyl halide and sodium bromoacetate to produce monoethers in high yields. Sucrose chelates in DMF solution react selectively with acid chlorides, cuihydrides and esters to produce sucrose monoesters or, in some cases, diesters as well. The yields and selectivities of the partial esterification of sucrose via chelates is higher than with other methods. The yield range of the acid derivatives studied are shown in Table XI. 

The chelates are prepared in anhydrous DMF or DMSO by ionization of the desired number of hydroxyl groups of the sucrose molecule with stoichiometric cunounts of sodium hydride to form alcoholates which, with metal salts, give the chelates. The etherification of sucrose with alkyl halides or esterification with organic acids caus is hydrolysis. The hydrolysis or diether formation is avoided if sucrose chelate is etherified at moderate temperatures and with only a small excess of allyl halide or sodium bromoacetate, giving 55-69% mono- and 0-2% diallyl ethers respectively, 41-48% mono- and 4-7% dicarboxymethyl ethers of sucrose. 

Aliev et al. reported the use of isothermal in situ solid-state NMR spectroscopy at 120, 130, and 140 °C to follow the synthesis of poly(hydroxyacetic acid) (polygly-colide) through the thermally induced solid-state polymerization reactions in sodium chloroacetate and sodium bromoacetate. Solid-state Na-NMR spectra recorded at 130 °C (in sodium bromoacetate) and 140°C (in sodium chloroacetate) were used to probe the sodium halogenoace-tate parent phase and the sodium halide (NaCl, NaBr) formed in the reactions. The experiments tracked the sodium ions as... 

Aliev AE, Elizabe L, Kariuki BM, Kirschnick H, Thomas JM, Epple M, Harris KDM. In situ monitoring of solid-state polymerization reactions in sodium chloroacetate and sodium bromoacetate by Na and C solid-state NMR spectroscopy. Chem Eur J 2000 6 1120-1126. 

The interaction of heterocyclic hydroxy- and potential hydroxy-compounds with hexamethylphosphoric triamide (H MPA) at 220— 230 °C replaces the hydroxy- with a dimethylamino-group. The numerous examples include the conversion of saccharin into 3-dimethylaminobenzisothiazole 5 5 -dioxide. In the presence of pyrrolidine, the 3-(l -pyrrolidyl)-compound is obtained. Improved yields of iV-carboxymethyl-l,2-benzisothiazolin-3-one 1,1-dioxide have been obtained from sodium saccharin by the action of sodium bromoacetate, or chloroacetonitrile, followed by hydrolysis. ... 

Preparation of REAOENTS.t It is essential for this preparation that the zinc powder should be in an active condition. For this purpose, it is usually sufficient if a sample of ordinary technical zinc powder is vigorously shaken in a flask with pure ether, and then filtered off at the pump, washed once with ether, quickly drained and without delay transferred to a vacuum desiccator. If, however, an impure sample of zinc dust fails to respond to this treatment, it should be vigorously stirred in a beaker with 5% aqueous sodium hydroxide solution until an effervescence of hydrogen occurs, and then filtered at the pump, washed thoroughly with distilled water, and then rapidly with ethanol and ether, and dried as before in a vacuum desiccator. The ethyl bromoacetate (b.p. 159 ) and the benzaldehyde (b.p. 179 ) should be dried and distilled before use. 

Ethyl bromoacetate (1). Fit a large modified Dean and Stark apparatus provided with a stopcock at the lower end (a convenient size is shown in Fig. Ill, 126, 1) to the 1-htre flask containing the crude bromoacetic acid of the previous preparation and attach a double surface condenser to the upper end. Mix the acid with 155 ml. of absolute ethyl alcohol, 240 ml. of sodium-dried benzene and 1 ml. of concentrated sulphuric acid. Heat the flask on a water bath water, benzene and alcohol will collect in the special apparatus and separate into two layers, the lower layer consisting of approximately 50 per cent, alcohol. Run ofi the lower layer (ca. 75 ml.), which includes all the water formed in the... 

In a 1-1, three-necked, round-bottomed flask equipped with a calcium chloride drying tube, a mechanical stirrer, and a ground-glass stopper are placed 28.2 g. (0.184 mole) of freshly distilled methyl bromoacetate, 500 ml. of anhydrous iV,iV-dimethy]acetamide (Note 1), and 20.0 g, (0.168 mole) of methyl nitroacetate (Note 2). The solution is stirred vigorously while 146 ml. (0.168 mole) of 1.15N sodium methoxide in... 

Reduction of the quaternary immonium salt 161, obtained by treatment of l-methyl-2-ethylidenepyrrolidine with ethyl bromoacetate, by means of either sodium borohydride or formic acid, leads to (—)-erythro-2-(2-N-methylpyrrolidyl)butyric acid (162), in agreement with Cram s rule (196). 

The mixture was filtered, the ethyl acetate layer separated and washed with three 100 ml portions of water, dried over Na2S04, filtered and treated with 30 ml of sodium 2-ethyl-hexanoate in n-butanol (34 ml = 0.1 mol). The oil which settled out was scratched to induce crystallization. After stirring for 20 minutes the product, sodium 7-(a-bromoacet-amido)cephalosporanate, was scraped from the sides of the flask and collected. The filter cake was washed with several portions of acetone, air dried, and dried in vacuo over P Os. The yield was 22.5 g and decomposed at 193°C. 

In semiindustrial synthesis, to achieve better yields, it is possible to omit (A), by directly preparing the ester (B) by reaction of p-hydroxy acetophenone on ethyl 2-bromoacetate in the presence of potassium carbonate in butanone. The yield of ester is 90%, and elimination of excess of p-hydroxyacetophenone is effected by washing with sodium hydroxide. 

Azatadine maleate Chlorprothixene Cyproheptadine iphenidol Flupentixol Heptabarbitol Mepivacaine Methadone HCI Methallenestril Methohexital sodium Oxitropium bromide Pipethanate ethobromide Pyrithyidione Ethyl bromoacetate Aceclidine... 

The monothione 2 (vide supra) is converted into the (methylsulfanyl)benzoxazepinone 3a by sodium hydride/iodomethane an analogous reaction with ethyl bromoacetate gives the ester 3b.37... 

An unprecedented ring contraction of the 7-azapteridine system has been observed when fervenulone 109 reacts with r-butyl bromoacetate using potassium carbonate/acetonitrile to yield 110 and the 0-alkylate in a 7 1 ratio. The mechanism proposed for this reaction is shown in Scheme 18. The use of sodium hydride/DMF yields the A-alkylated product 111 <95JOC7063>. 

With the A-ring unit readily available, we directed our attention to the formation of the B-ring. At first, we duplicated the five step scheme reported in Sih s strigol synthesis involving 1) esterification of the acid 14, 2) allylic bromination with N-bromo 8 ucc i n imi d e (NBS) to 15, 3) condensation with the sodium salt of dimethyl malonate to 16, 4) alkylation with methyl bromoacetate to 17, and 5) acid catalyzed hydrolysis and decarboxylation to the acid 18. 

Thus, the reaction of alkyl halides and a-halo esters with sodium nitrite provides a very useful synthetic method for nitroalkanes and a-nitro esters. However, ethyl bromoacetate is exceptional in that it fails to give ethyl nitroacetate on treatment with sodium nitrite.93 This is due to the acidic hydrogen of the ethyl nitroacetate, which undergoes a further reaction with sodium nitrite to give the oxidized products (see Section 6.1, which discusses the Nef reaction). In a similar way, the reaction of benzyl bromide with sodium nitrite at 25 °C gives benzoic acid predominantly. To get phenylnitromethane, the reaction must be carried out at low temperature (-16 °C) (Eq. 2.48).93... 

The procedure given above is essentially a large-scale adaptation of that of Filachione.2 Bromoacetal has been prepared by the bromination of acetal directly,3 or in the presence of calcium carbonate 4 by action of sodium ethoxide on a,/3-dibromodiethyl ether by bromination of paraldehyde followed by action of ethyl alcohol 6 and by the action of ethyl alcohol on bromoacetal-dehyde.7... 

Compounds 161 and 162 were found to be unstable in basic, protic media, presumably due to the presence of the acidic hydrogen atom of the malonic ester. As a result, their synthetic utility is somewhat limited. It was, however, found possible to alkylate 162 with ethyl bromoacetate in the presence of sodium hydride,125 to give triethyl 1 - (2,3,5-tri-O-benzoyl- /3-d-ribofuranosyl) -1,1,2-ethanetricarboxylate (166). This product was obtained in 20% yield by treatment of 81... 

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