A-bromopropionate

Ethyl a-bromopropionate. This preparation illustrates the facile bromination of an acid chloride (propionyl chloride) in the presence of red phosphorus, and the subsequent conversion of the bromoacid chloride into the ethyl ester by direct interaction with ethanol. 

Chapter III. 1 Heptene (111,10) alkyl iodides (KI H3PO4 method) (111,38) alkyl fluorides (KF-ethylene glycol method) (111,41) keten (nichrome wire method) (111,90) ion exchange resin catalyst method for esters (111,102) acetamide (urea method) (111,107) ethyl a bromopropionate (111,126) acetoacetatic ester condensation using sodium triphenylmethide (111,151). 

The reaction of ethyl a-bromoacetate with 17-keto steroids such as estrone methyl ether or dehydroepiandrosterone acetate " under standard Reformatsky conditions is stereospecific, producing the 17 -ol in up to 80% yields. Ethyl a-bromopropionate reacts similarly but the yields are somewhat lower. 

Ethyl a-(1-pyrrolidyl)-propionate has been prepared by the reaction of pyrrolidine with ethyl a-bromopropionate.2... 

A final example is the synthesis of H-shaped copolymer of (PS PEG (PS)2 by ATRP, i.e. [209]. The synthetic strategy involves the synthesis of 2,2-bis(methylene a-bromopropionate) propionyl chloride (1), the preparation of 2,2-bis(methylene a-bromopropionate) propionyl-terminated poly(ethylene glycol) (BMBP-PEG-BMBP) (2), and then ATRP of styrene at 110 °C with BMBP-PEG-BMBP/CuBr/2,2/-bipyridine as the initiating system. The structure (3) was configured by using NMR and SEC measurements (Scheme 116). 

Ethyl a-bromopropionate is available commercially (Sapon Laboratories, % 1.4452) and is employed without purification. Bromo esters are severe lachrymators, and operations that involve transferring these compounds from one vessel to another should be conducted in a well-ventilated hood. 

Eastman grade ethyl a-bromopropionate was used as obtained from Eastman Organic Chemicals. 

Ethyl isocyanide, 46, 76, 77 Ethyl a-(isopropylideneaminooxy)pro-pionate, from acetone oxime and ethyl a-bromopropionate, 48,120 hydrolysis of, 48,121 Ethylmagnesium bromide, use with ferric chloride in cyclization of di-chloroacetone /J-Lolylmagncsium bromide adduct to l-f>-tolyicy-clopropanol, 47,108 Ethyl a-methyl-/3-phenylcinnamate, 48, 79... 

TAPA has been prepared only as described in this procedure.5 a-(Isopropylideneaminooxy)propionic acid has been prepared and resolved by the present procedure 6 and has been prepared directly from a-bromopropionic acid and resolved as the (—)-ephedrine salt by crystallization from hydrocarbon mixtures.5... 

Selective N-alkylation of potassium phthalimide by ethyl a-bromopropionate"... 

L-Perhydro-l,4-thiazine-3-carboxylic acid 1-oxide is a natural AA found in some red and brown algae. It was synthesized from L-cystine in several steps. The heterocyclic ring was prepared by cyclization of 5-(2-chloro- or bromoethyl)-L-Cys in the presence of triethylamine. Perhydro-l,4-thiazine-3-carboxylic acid was then oxidized with H2O2/ACOH to give the sulfoxide (64JOC2203). Cystine also reacted with ethyl a-bromopropionate in liquid ammonia to give 5-oxoperhydro-l,4-thiazine-3-carboxylic acid [76JCS(P2)203],... 

The Reformatsky reactions of ethyl a-bromopropionate and related esters with N-substituted 6-bromo-2-oxochromene-3-carboxamides in a mixed diethyl ether-benzene-HMPA-THF solvent system give substituted 9-bromo-2,3,4,4a,5,10b-hexahydro-l//-chromeno[3,4-f]pyridine-2,4,5-triones (HMPA = hexamethylphosphoramide Scheme 45) <2004RJ0892>. Without the THF present in the mixed-solvent system, the reaction stops at the intermediate Wbenzyl-6-bromo-4-(l-alkoxycarbonylalkyl)-2-oxochroman-3-carboxamide stage. 

Ethyl a-bromopropionate [535-11-5] M 181.0, b 69-70 /25mm, d 1.39, n 1.447. Washed with saturated aqueous Na2CO3 (three times), 50% aq CaCl2 (three times) and saturated aqueous NaCl (twice). Dried with MgSOa, CaCl2 or CaCO3, and distd. LACHRYMATORY. 

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