Dl Isoleucine

This compound, when treated with nitrosyl sulphate was decomposed into a-oximino-sec-butylacetic acid, which, on reduction with zinc dust and hydi ochloric acid in alcohol, gave a 60 per cent, yield of dl-isoleucine —... 

C) dl-Isoleucine.—One hundred and fifty grams (0.77 mole) of a-bromo-/3-methyl valeric acid is added to 645 cc. of technical ammonium hydroxide (sp. gr. 0.90) in a 1.5-I. round-bottomed flask. A stopper is wired in and the flask allowed to stand at room temperature for a week (Note 9). The stopper is removed and the mixture heated on a steam cone overnight to remove ammonia. The aqueous solution is concentrated under reduced pressure until bumping becomes violent (about 300 cc.). The mixture is then cooled to 150 and the crystals collected on a filter. The crystals are washed with 40 cc. of alcohol and dried. The filtrate is again concentrated to about 150 cc. and a second crop of crystals obtained. This second crop is washed with 25 cc. of water and then with 25 cc. of 95 per cent alcohol. The yield of crude product is 65 g. 

DL-Isoleucine (2-amino-3-methylpentanoic acid). Allow 65 g (0.33 mol) of 2-bromo-3-methylpentanoic acid (Expt 5.166) to react with 400 ml of concentrated ammonia solution as for valine. Concentrate the resulting solution to about 130 ml, filter off a first crop of crude product and wash with 20 ml of ethanol. Further concentrate the aqueous filtrate to about 60 ml to obtain a second crop of crude product, and wash it with 10 ml of water followed by... 

DL-Isoleucine occurs as a white, crystalline powder. It is soluble in water, and practically insoluble in alcohol and in ether. It melts with decomposition at about 292°. The pH of a 1 100 aqueous solution is between 5.5 and 7.0. It is optically inactive. 

Insoluble Sodium Metaphosphate, 52 Insoluble Sodium Polyphosphate, 52 Isoamyl Alcohol, 78 Isoamyl Benzoate, 78 Isoamyl Butyrate, 78 Isoamyl Phenyl Acetate, 78 Isoamyl Salicylate, 78 Isobutyl Cinnamate, 78 Isobutyl Isovalerate, 84 Isobutyraldehyde, 78 DL-Isoleucine, 30 L-Isoleucine, 31 Isopropyl Acetate, 80... 

ISOKETsee CCKI25 ISOL see HFP875 ISOLAN see DSK200 ISOLANE (FRENCH) see DSK200 ISOLEUCINE see IKXOOO ISOLEUCINE see IKXOOO dl-ISOLEUCINE see IKXOlO... 

In a similar manner 2-s-butyl-3-hydroxy-54sobutylpyrazine was prepared from DL-leucyl-DL-isoleucine anhydride, 3-s-butyl-6-isobutylpiperazine-2,5-dione, and phosphoryl chloride (93,313). 

DL-Isoleucine hydroxamic acid Diacetyl 3-s-Butyl-2-hydroxy-5,6-dimethyl 547... 

In the desulfurization of 3-substituted thiophenes several stereoisomers may be formed in certain cases. Both meso and racemic compounds have been obtained from the desulfurization of 3,4-diaryI-substituted thiophenes. It is claimed, however, that only meso jffj -diphenyladipic acid is obtained upon desulfurization of 3,4-di-phenyl-2,5-thiophenedicarboxylic acid and only dl-isoleucin from 3-thienylglycine. The formation of small amounts of dimeric products in the desulfurization has been discussed with reference to the mechanism of this reaction. ... 

Resolution The carbobenzoxy derivatives of DL-proline, DL-alanine, and dl-isoleucine have been resolved by fractional crystallization, in the lower alcohols or water, of the diastereoisomeric salts with L-tyrosine hydrazide. The yield is low in the case of DL-phenylalanine. 

Shiraiwa, T., Ikawa, A., Sakaguchi, K., Kurokawa, H. (1984). Optical resolution of DL-valine, DL-leucine, and DL-isoleucine by formation of adduct with L-pheny-lalanine. Bull. Chem. Soc. Jpn 57 2234. 

L-Histidine, DL-isoleucine, L-leucine, D-mannose, L-methionine, L-proline, L-rhamnose, DL-serine, L-tryptophan... 

Amino-4-methylvaleric acid. See L-Leucine 2-Amino-3-methylvaleric acid. See L-lsoleucine 2-Amino-4-methylvaleric acid. See L-Leucine a-Amino-p-methylvaleric acid. See L-lsoleucine a-Amino-y-methylvaleric acid. See L-Leucine D-2-Amino-4-methylvaleric acid. See D-Leucine DL-2-Amino-3-methylvaleric acid. See DL-Isoleucine... 

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