Hypochlorite reactions with amino acids

Hypochlorous acid reacts very rapidly and quantitatively with a slight excess of free ammonia forming monochloramine, NH2CI, which reacts at a slower rate with additional HOCl forming dichloramine, NHCI2. Trichloramine is formed when three moles of HOCl are added per mole of ammonia between pH 3—4 (100). Hypochlorous acid in the form of chlorine or hypochlorite is used in water treatments to oxidize ammonia by the process of break-point chlorination, which is based on formation of unstable dichloramine. The instabiHty of NHCI2 is caused by presence of HOCl and NCl (101,102). The reaction is most rapid at a pH of about 7.5 (103). Other nitrogen compounds such as urea, creatinine, and amino acids are also oxidized by hypochlorous acid, but at slower rates. Unstable iV-chloro compounds are intermediates in deammination of amino acids (104,105). 

Reactions of a number of l-phenylimidazole-2-carboxamides with chlorine in acetic acid, NCS, or hypochlorite failed to introduce chlorine into the 4- or 5-positions (80JHC409). Chlorination of a variety of 2,4-disubstituted imidazoles, however, was quite facile, Thus, 2,4-diesters [83JCS(P1)809] and 2-amino-4-aryl compounds [80IJC(B)526] were readily 5-chlorinated, and even when both the 4- and the 5-positions were blocked, as in 5-aminoimidazole-4-carboxamide, 2-chlorination with iodine monochloride was possible (89MI5). When all three carbons were substituted (e.g., in 2,4,5-triphenyl-, 2-chloro-4,5-diphenyl-, and 2-trichloromethyl-... 

Synthesis of enamines from amino acids has been described518. Van Tamelen and coworkers519 have described a useful method for the preparation of enamines by the oxidative decarboxylation of N,N-dialkyl-a-amino acids with sodium hypochlorite. Synthesis of enamines by the Babyan rearrangement-cleavage reaction has been described520. 

Anuno acids are converted into aldehydes, the most popular method being the Strecker degradatioa The amino acid is simply mixed with reagoits such as niitiiydrin and heated to form ammonia and carbon dioxide as by-products. Sodium hypochlorite can be used in a process accelerated by UV irradiation. A similar reaction is the Akabori reaction where the amino acid is heated with compounds such as glucose to give alddiydes, as in the Strecko process. ... 

Using a carboxamide group as a source of an amino group by applying Hoffman type reactions, it has been possible to prepare several purines. Thus 4-aminopyrimidine-5-carboxamide and alkaline hypochlorite gave, a 60% yield of 8-oxo-7,8-dihydropurine (302) (62CB956), and the same authors achieved a Curtius reaction with a 4-aminopyrimidine-5-carbohydrazide and nitrous acid (Scheme 113). 

Studies on the transamination reaction between f-butyl esters of optically active amino acids and methyl pyruvate were carried out, as shown in Scheme 7. The resulting iminodicarboxylic acid (16) was partially hydrolyzed and then oxidized with f-butyl hypochlorite to form alanine. The oxidation is a generally applicable one, and the optical purity of alanine is high (50-70%). Similar asymmetric transamination between an (S)-amino acid and ketones was carried out. Catalytic hydrogenation of the Schiff s bases prepared from a-keto acid esters and amino acid esters was carried out, and a substituent and temperature effect observed (de 40-70%). ... 

AMINO-2,4-DIMETHYLBENZENE (95-68-1) Combustible liquid (flash point 205°F/ 96°C). Violent reaction with strong oxidizers, strong acids, nitrosyl perchlorate. Mixtures with hypochlorites form sensitive explosive chloroamines. Incompatible with aldehydes, nonoxidizing mineral acids, cellulose nitrate (of high surface area), cresols, isocyanates, nitrates, nitric acid, organic anhydrides, phenols, sulfuric add. 

Treatment of adenosine with sodium toluene-p-sulphinate and sodium hypochlorite gives a 50% yield of 2 -0-tosyladenosine. iV-Chloro intermediates are thought to be involved, which then give tosyl chloride by reaction with the sulphinate, but it is unclear why this procedure gives a higher yield than direct tosylation.229 Amino acids linked to (deoxy)-nucleosides via a sulphamoyl group have been reported they are structurally similar to the antibiotic ascamycin (see also Vol. 23, p.226).230 3. and 5 -0-dansyl derivatives of thymidine have been prepared, and shown to act as inhibitors of thymidine kinase from herpes simplex virus.231... 

Aliphatic a-amino acids, and also aromatic ones with the amino group bound on an aliphatic side chain, give a color reaction with ferric chloride a red color is formed, disappearing on addition of acid. They also react with copper (II) chloride (for example, if an aqueous or alcoholic solution of an amino acid is boiled with copper (II) oxide or carbonate, a blue color is formed) or with alkali hypochlorites (aliphatic a-amino acids), which give rise to the next lowest aldehyde, for example (72),... 

---