Bromophenylacetic acid

Scheme 9.4 Proposed route to amine 2 starting from 3-bromophenylacetic acid.

Alkylation of the dianion of 3-bromophenylacetic acid (10) with p-chlorobenzyl chloride was accomplished using IiHMDS in THF to afford the substituted acid 11. The only significant impurity was the bis-alkylated product, which could be minimized by control of the reaction temperature to below -20 °C to give an 88%... 

The reaction of potassium 3-amino-4-oxo-3,4-dihydroquinazoline-2-thiolate 62 with a-bromophenylacetic acid 63 resulted in the formation of (3-amino-4-oxo-3,4-dihydroquinazolin-2-ylsulfanyl)-phenyl-acetic acid methyl ester 64 which on alkali treatment and subsequent acidification resulted in the synthesis of 2-phenyl- 1-thia-4,4a,9-triaza-anthracene-3,10-dione 65 <1999JCR(S)86>. Similarly, the reaction of potassium 3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- pyrimidine-2-thiolate 66 with a-bromo-ester 67 resulted in the formation of 2-(3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- / pyrimidin-2-ylsulfanyl)-propionic acid ethyl ester 68. Subsequent treatment with alkali followed by acidification resulted in the formation of 2,3,7-trimethyl-3a,9a-dihydro-l,8-dithia-4a,5,9-triazacyclopenta[ ]naphthalene-4,6-dione 69 <2000JHC1161>... 

Fig. 5. Inhibition mode of a-bromophenylacetic acid against AMDase-catalyzed decarboxylation. Lineweaver-Burk plot in the presence of the acid A, 100 pM B, 20 pM C, 0 pM...

As deduced from the DNA sequence of the gene, AMDase contains four cysteine residues. Since a-halocarboxylic acids are generally active alkylating agents there is a possibility that a-bromophenylacetic acid reacts with several cysteine residues of the enzyme. Therefore, we tried to clarify how many cysteine residues react with this inhibitor. It is well established that when p-chloromercuri-benzoate (PCMB) binds to a cysteine residue, the absorbance at 255 nm increases due to the formation of an aryl-Hg-S bond. Thus it is possible to estimate the number of free S-H residues of the enzyme by titration with PCMB solution (Fig. 6). When the native enzyme had reacted with PCMB, the absorbance at 255 nm increased by 0.025. On the other hand, when PCMB solution was added to the enzyme solution after the enzyme was incubated with a-bromophenyl-... 

Thienyl tellurolates also remove several different substituents such as acetoxy, mesyloxy, phenylthio and 2-thienyltelluro groups, as well as effect the reductive dehalo-genation of bromoacetanilide, and of a-haloacids (such as a-bromophenylacetic acid, a-bromo-l-naphthylacetic acid and a-chlorodiphenylacetic acid). ... 

Method C2 (typical catalytic procedure).A 5% solution of NaBH4 in 5% aqueous NaOH is added dropwise under N2 to a solution of a-bromophenylacetic acid (1.50 g, 7.0 mmol) and bis(2-thienyl) ditelluride (0.30 g, 0.71 mmol) in EtOH (40 mL) until the red colour of the ditelluride just disappears. At this point air is infioduced in the system to oxidize the catalyst back to the ditelluride. The mixture is then partitioned in ether/5% aqueous NaOH. The aqueous phase is separated, acidified with 2 M HCl and extracted with ether. The extract is dried (CaCl2) and evaporated to give phenylacetic acid (0.93 g (98%) m.p. 77°C). 

Carboxylic acids, acyl chlorides, and sulfonyl chlorides used for deri-vatization of 4-aminophenylalanine and >-4-am i n op h e ny I a I a n i n e are as follows 5-hydantoinacetic acid, / ran, v - 4 - co t i n i n ec a r b o xy I i c acid, isonicotinic acid, 3-pyridinepropionic acid, 4-hydroxyphenylacetic acid, 2-butynoic acid, 2-pyrazinecarboxylic acid, cyclopropanecarboxylic acid, 3-hydroxy-2-qui-noxaline carboxylic acid, 5-bromovaleric acid, propargyl chloroformate, 3,4-dimethoxybenzoyl chloride, 2-thiophenesulfonyl chloride, 3-thiophene-carboxylic acid, 2-thiophenecarboxylic acid, 2-methylbutyric acid, 2-thio-pheneacetyl chloride, benzoic acid, furylacrylic acid, 4-nitrophenyl acetic acid, 2,5-dimethoxyphenylacetic acid, p-toluenesulfonyl chloride, 4-(di-methylamino)phenylacetic acid, 3-indolepropionic acid, phenoxyacetic acid, 3-(dimethylamino)benzoic acid, cyclohexanecarboxylic acid, naphtha-lenesulfonyl chloride, 4-bromophenylacetic acid, 4-bromobenzoic acid, 2-phenoxybutyric acid, 3,4-dichlorophenylacetic acid, (l-naphthoxy)acetic acid. 

Anhydro-4-hydroxy-2,3,5-triphenyl-l,3-selenazolium hydroxide (65) is prepared by a multistep reaction selenobenzanilide (63) reacts with a -bromophenylacetic acid to give the a -seleno add (64) this acid readily cyclizes to the mesoionic selenazole (65), which upon reaction with DMAD affords an unstable adduct which by extrusion of selenium gives the pyridone diester (66 Scheme 23) (75CC617). 

Pyrrolo[2,l-4 [l,5]benzothiazocine 563a was prepared by alkylation of thiophenol 602 with a-bromophenylacetic acid 603 that furnished the carboxylic acid 604 (73% yield) which, by an intramolecular cyclization in presence of PCl5, yielded 563a (41% yield) (Scheme 121) <1997EJM241>. 

A mixture of 4-bromophenylacetic acid (0.800 mol), 2-amino-2-methyl-l-propanol (1.20 mol) and 900 ml xylenes were refluxed for 24 hours, cooled, filtered, and concentrated. Precipitated crystals were slurried in hexanes and the product isolated in 75% yield. 

Carbon-11 labeled BPA, 4, was synthesized from the corresponding aldehyde, 4-boronophenylacetaldehyde, 9. This boronated aldehyde was prepared from commercially available 4-bromophenylacetic acid, 10, in five synthetic steps (Scheme 1). The synthesis was initiated by the borane reduction8 of acid 10 to the 2-(4-boronophenyl)ethyl alcohol, 11. Alcohol 11 was then carefully oxidized9 to aldehyde 12. In the next step, 4-bromophenylacetaldehyde, 12, was refluxed with ethylene glycol in the presence of a catalytic amount ofp-toluenesulfonic acid to obtain the corresponding acetal 13.10 The boronic acid moiety was introduced at the para position of the phenyl ring by the reaction with butyllithium followed by triisopropyl borate" to obtain the 4-bronophenylacetaldehyde ethylene acetal, 14. In the final step of the synthesis, acetal 14 was treated with concentrated hydrochloric acid in methanol as solvent to obtain the desired precursor, 4-boronophenylacetaldehyde, 9, for the synthesis of carbon-11 labeled BPA, 4, Scheme 2. 

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