Bromoacetic acid ester

In addition, there exists a group of carboxylic acid functionalised carbene ligands that have the appearance of being derived from the amino acid glycine, but their synthesis was actually achieved by quartemising N-substituted imidazole with a bromoacetic acid ester [71,72], A representative example for this synthetic route is presented in Figure 6.29. 

IVB could be prepared according to the description in Sect. 5.1.2. The substituted phenoxyacetyl chlorides MS could be easily synthesized starting from substituted phenols and chloroacetic acid or bromoacetic acid ester [45, 46], as... 

A treatment of 2-butyltelluroaniline with an equimolar amount of bromoacetic acid results in spontaneous cyclization of the formed telluronium salt 31 to give 1-butylbenzotellurazinonium bromide 30. That the alkylation occurs at the tellurium and not at the nitrogen atom of 2-butyltelluroaniline has been proved by the isolation of the methyl ester of 31 in 60% yield when the amine was coupled with methyl bromoacetate under the same reaction conditions. Elimination of butyl bromide from 30 readily occurs on heating of its DMF solution leading to 2//-l,4-benzotellurazin-3(4//)-one 32 in 90% yield. 

Diethylaminoethyl)acetic acid ethyl ester Bromoacetic acid ethyl ester... 

Fluocinolone acetonide Fluocortolone Fluoxymesterone Bromoacetic acid ethyl ester Chromonar HCI Bromoacetol... 

Antoracemisation has been observed with substances not only in solid or liquid states but also in their solutions, For Example (+)-phenyl bromoacetic acid after three years of storage becomes inactive, in its solid state. A liquid showing antoracemisation is the ethyl ester of bromosuccinic acid. 

Hydroxycynnclidine (14.1.17) is synthesized from the methyl ester of wo-nicotinic acid, which is reacted with the ethyl ester of bromoacetic acid to give the piridinium salt (14.1.14). This is rednced by hydrogen nsing a platinnm catalyst, giving 1-carbethoxymethyl-... 

Lipo-amino acid derivatives are readily obtained in good yields by direct alkylation of amino acids esters with the related alkyl halides, e.g. farnesyl bromide, under careful control of the reaction conditions to avoid exhaustive alkylation of the amino group. 128 Alternatively, peptoid chemistry is applied for N-alkylation of glycine ester via reaction of alkyl amines, e.g. hexadecylamine, with ethyl bromoacetate. 36,98 ... 

Alkylation at N( 5) of the cyclic intermediates 38 was accomplished using concentrated solutions of alkyl halides in DMF at 50°C. Addition of a base proved not only unnecessary but even counterproductive in terms of the purity of the resulting Al(5)-substituted benzodiazepi nones 39. Alkyl halides producing good results in this reaction include more than 40 benzyl bromides, allyl bromide, various esters of bromoacetic acid, as well as methyl and ethyl iodide. Other alkyl iodides, along with benzyl chlorides and a-bromo acetophenones, however, did not give satisfactory results. 

This procedure was improved 123 for the synthesis of building units based on amino acids other than Gly, but with nonfunctionalized side chains (Table 6). To suppress the 3-elim-ination and racemization side reactions, triflates of a-hydroxycarboxylic acid esters 124 34 (L = OTf, Scheme 19) were used as substrates for the nucleophilic substitution. In order to prevent polyalkylation, the nucleophilic amine of to-BocNH- or co-tBu02C-alkylamines 33 were temporarily protected with the benzyl group. 115116 This protection also improved the yields and purity of Gly-based building units. In this case commercially available benzyl bromoacetate 34 (L=Br) was used as the substrate. In both cases the nucleophilic sub-... 

Fused l,2,5-triazepine-3,6-diones 88-90 were synthesized from (2 S )-proline methyl ester 205 by treating the latter with bromoacetic acid 206 in the presence of tiro-butyl chloroformate 207 (Scheme 46). The resultant bromoacetamide 208 on further treatment with hydrazine hydrate in EtOH gave 88-90 via cyclization through displacement of bromine <1996CC85>. 

Alternatively, bromoacetic acid could be converted to the corresponding acyl chloride, then treated with ethanol. It would be incorrect to try to brominate ethyl acetate the Hell-Volhard-Zelinsky method requires an acid as starting material, not an ester. 

Alkylation of the corresponding dianion of acid 32 was very convenient and led to numerous 9-alkyl products. For example, analogue 58 was prepared via the LDA-generated dianion of 32, which was alkylated with f-butyl bromoacetate to provide acid-ester 64. Crude vinylsilane 64 was submitted to successive ozone addition and acidification. The resultant tetracyclic peroxide 65 was subsequently treated with trifluoroacetic acid to cleave the f-butyl ester to the free the acetic acid appendage of target 58 in 20% overall yield from 64 (Eq. 15). 

Alcohol 6 is prepared by a copper-catalyzed reaction of (R)-benzylglycidyl ether with vinylmagnesium bromide. The first step here is a Williamson ether synthesis. The free alcohol 6 reacts with sodium hydride to a sodium alkoxide, which is treated with the sodium salt of bromoacetic acid. The acid is also converted into the sodium salt to avoid the formation of an ester as side product. After the reaction carboxylic acid 20 is released in 93 % yield by acidification with aqueous 10 % HC1 solution. 

Hydrolysis (especially with bromoacetic acid)28 of the dicarboxylic esters can be followed by decarboxylation and it is possible to remove one carboxyl group at a time to prepare the imidazole-4-carboxylic acid. The decarboxylation of imidazolecarboxylic acids has been discussed by Schipper and Day.2... 

A few years earlier, Herrmann et al. published a carboxylic ester functionalised imi-dazolium salt that was synthesised directly from imidazole and bromoacetic acid ethyl ester [216]. Owing to its method of synthesis the imidazolium salt is C -symmetric with two ester functional wingUp groups. Generation of the rhodium(I) and palladium(II) carbene complexes was realised by reaction of the imidazolium salt with a rhodium alkoxide precursor or with palladium(II) acetate in the presence of NaOEt and Nal (see Figure 3.76). The silver(I) oxide method had not been discussed in the literature at the time [11]. 

SYNS ANTOL BROMOACETIC ACID, ETHYL ESTER ETHOXYCARBONYLMETHYL BROMIDE ETHYL BROMOACETATE ETHYL-a-BROMOACETATE ETHYL MONOBROMOACETATE... 

SYNS BROMOACETIC ACID METHYL ESTER METHYL a-BROMOACETATE METHYLESTER KYSELINYBROMOCTOVE METHYL MONOBROMO-ACETATE... 

BROMOACETIC ACID, ETHYL ESTER see EGVOOO BROMOACETIC ACID METHYL ESTER see MHR250 BROMOACETONE see BNZOOO BROMOACETONE (DOT) see BNZOOO BROMOACETONE, Uquid (DOT) see BNZOOO... 

Before the turn of the century, Maquenne had prepared imidazole-4,5-dicarboxylates from tartaric ester dinitrates with either an aliphatic aldehyde or precursor in the presence of ammonium ions at pH values 3.5-6.S. Hydrolysis, especially with bromoacetic acid, of the resulting dicarboxylate esters gives imidazole-4,5-dicarboxylic acid (Scheme 75) <70AHC(12)103). 

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