Acetic acid bromo -, methyl ester

Methyl bromoacetate Acetic acid, bromo-, methyl ester (8,9) (96-32-2) Acetic anhydride (8) Acetic acid anhydride (9) (108-24-7)... 

The bromo methyl ester (212) formed by treatment of 30 with hydrogen bromide in acetic acid could also serve as a precursor to validamine. ... 

This synthesis came shortly after one by Prelog, Kohlberg, Cerkovnikov, Rezek and Piantanida (1937) based on a series of reactions which, with modifications and extensions. Prelog and his colleagues have applied to the syntheses of bridged heterocyclic nuclei, of which this is an example. 4-Hydroxymethyltetrahydropyran (VI R =. OH) is converted via the bromo-compound (VI R = Br) and the nitrile (VI R = CN) into tetrahydropyran-4-acetic acid of which the ethyl ester (VII) is reduced to 4-()3-hydroxyethyl)-tetrahydropyTan (VIII). This is converted by fuming hydrobromic acid into 3-(2-bromoethyl)-l 5-dibromopentane (IX) which with ammonia in methyl alcohol yields quinuclidine (V). 

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>... 

The next three procedures provide useful synthetic intermediates. A stereospecific synthesis of ETHYL (Z)-3-BROMO-2-PROPENOATE affords an alternative vinyl bromide partner for the coupling chemistry in the preceding procedure. A very simple but elegant illustration of the flash vacuum pyrolysis technique is used to prepare BENZOCYCLOBUTENONE from o-toluoyl chloride. Another member of the functionalized indole family of synthetic intermediates is presented in a four-step procedure for 5-METHOXYINDOLE-2-ACETIC ACID METHYL ESTER. 

Alternatively, a-bromo-(2-chlorophenyl)acetic acid (15) was prepared by treatment of 2-chlorobenzaldehyde with tribromomethane in dioxane with an aqueous solution of potassium hydroxide, Fonnation of methyl ester 16 was followed by an Sn2 displacement by thieno[3,2-c]pyridine (8) to afford ) an 88% yield of ( )-clopidogrel (2 in two steps. 

Synthesis (Kleemann et al. 1999, Janssen (Janssen), 1973 Janssen et al. (Janssen), 1973, Stokbroekx et al., 1973, Niemegeers et al., 1974) ) Treatment of 2-oxo-3,3-diphenyl-tetrahydrofuran, synthesized by treatment of diphenyl-acetic acid ethyl ester with ethylene oxide, with HBr(gas) yields bromo derivative i, which is then converted into butyryl chloride derivative ii by means of thionyl chloride in refluxing chloroform. Reaction of derivative ii with dimethylamine in toluene affords dimethyl (tetrahydro-3,3-diphenyl-2-furylidene)ammonium bromide, which is then condensed with 4-(4-chlorophenyl)-4-piperidinol by means of Na2C03 and Kl in refluxing 4-methyl-2-pentanone to provide loperamide. 

This compound with hydriodic acid in acetic acid in the presence of red phosphorous at reflux yielded 5,7-dihydroxy-4-methyl-3H-isobenzofuran-l-one. Condensation of 6-bromo-4-methylhex-4-enoic acid methyl ester and 5,7-dihydroxy-4-methyl-3H-isobenzofuran-l-one with silver oxide in dioxane at room temperature yielded 6-(4,6-dihydroxy-7-methyl-3-oxo-l,3-dihydro-isobenzofuran-5-yl)-4-methylhex-4-enoic acid methyl ester (36% yield). At last, monomethylation with diazomethane yield 6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-l,3-dihydro-isobenzofuran-5-yl)-4-methylhex-4-enoic acid... 

A synthetic route to ( )-0,f>-dimethyltubocurarine iodide (CXXV), via the racemate of 0,0-dimethylbebeerine (CXXIII), was announced in 1959 by Tolkachev and his collaborators (94). It started by the condensation of 3-methoxy-4-hydroxyphenethylamine with 4-benzyloxy-phenylacetic acid to give the amide CXXVI. Reaction of the potassium salt of the latter with the methyl ester of 3-bromo-4-methoxyphenyl-acetic acid in the presence of copper powder gave compound CXXVII. This on condensation with 3-methoxy-4-hydroxy-5-bromophenethyl-amine afforded compound CXXVIII, which was methylated to CXXIX. The latter compound was cyclized with phosphorous oxychloride to the dihydroisoquinoline derivative CXXX. Debenzylation of CXXX followed by intramolecular Ullmann condensation yielded compound CXXXI. The latter was converted to racemic dimethylbebeerine (CXXIII) by reduction with zinc dust in acetic acid followed by methyla-tion. Finally, treatment of ( + )-CXXIII with methyl iodide furnished the dimethyl ether of ( + )-tubocurarine iodide, identified by comparison of its UV-spectrum with that of the dimethyl ether of natural tubo-curarine iodide and by melting-point determination of a mixture of the two specimens. 

The ammonium formate in formic acid procedure has rendered possible the first preparation of isomeric 4,5-disubstituted oxazoles.03101 Bredereck, Gompper, and Reich101 have reported the anomalous behavior of certain long-chain a-bromo ketones a single a-bromo ketone on reaction with ammonium formate in formic acid gives a mixture of two isomeric oxazoles. Refluxing of a-bromo ketones or of a-chloro-/3-keto esters with ammonium acetate in acetic acid results in the formation of substituted 2-methyl-oxazoles.40 102 Ethyl a-chloroacetoacetate on heating with ammonium carbonate or formamide in formic acid yields 4-methyloxazole-5-carboxylic ester.40 103... 

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