Chloramine secondary amines

Organoboranes react with a mixture of aqueous NH3 and NaOCl to produce primary amines. It is likely that the actual reagent is chloramine NH2CI. Chloramine itself,hydroxylamine-O-sulfonic acid in diglyme, and trimethyl-silyl azide " also give the reaction. Since the boranes can be prepared by the hydroboration of alkenes (15-16), this is an indirect method for the addition of NH3 to a double bond with anti-Markovnikov orientation. Secondary amines can be prepared by the treatment of alkyl- or aryldichloroboranes or dialkylchlorobor-anes with alkyl or aryl azides. 

Primary and secondary amines and amides are first chlorinated at nitrogen by the chlorine released by the gradually decomposing calcium hypochlorite. Excess chlorine gas is then selectively reduced in the TLC layer by gaseous formaldehyde. The reactive chloramines produced in the chromatogram zones then oxidize iodide to iodine, which reacts with the starch to yield an intense blue iodine-starch inclusion complex. 

Primary amino acids will react with o-phthalaldehyde in the presence of the strongly reducing 2-mercaptoethanol (pH 9-11) to yield a fluorescent product (emission maximum, 455 nm excitation maximum, 340 nm). Peptides are less reactive than a-amino acids and secondary amines do not react at all. As a result, proline and hydroxyproline must first be treated with a suitable oxidizing agent such as chloramine T (sodium A-chloro-p-toluene-sulphonamide) or sodium hypochlorite, to convert them into compounds which will react. Similarly cystine and cysteine should also be first oxidized to cysteic acid. 

The A -methyl derivative (32) was obtained from 31 via a Leuckart reaction and isolated as its hydrochloride 32 is also formed in the Hoffmann-Lbflfterreaction(photolysisinsulfuricacid)ofthei r-chloramine (33), since after separation of secondary amines and addition of methyl iodide a 10% yield of the methiodide (34) was obtained. The secondary amine (31) was also converted to its A-acyl and JV -nitroso derivatives (35-37) and (38), respectively, by conventional procedures. Free-radical chlorination of 37 gave the ca o-2-chloro derivative (39) and... 

The reaction of trialkylboranes with iV-chloroalkylamines can be used to synthesize a wide variety of functionally substituted dialkylamines in good yields [66,67], and it complements the synthesis of secondary amines via the reaction of trialkylboranes with organic azides. The reaction is analogous to the reaction of chloramine with organoboranes, and presumably occurs via an anionotropic migration of an alkyl group from boron to nitrogen (Scheme 24). 

Chloramines. This reagent chlorinates primary and secondary amines, but is most useful for chlorination of hindered amines. The reaction is carried out in water or benzene-water. The co-product, cyanuric acid, is removed by filtration. 

Hydroxylamine-O-sulfonic acid (aminyl hydrogen sulfate) has often proved superior to chloramine for amination the former is a stable crystalline substance that can be easily handled and weighed. It aminates primary279,280 and secondary amines280 to hydrazines, and tertiary amines to hydrazinium salts.28<> It is a stronger animating agent than chloramine as it converts pyridine into the 1-aminopyridinium salt, a reaction that cannot be carried out by chloramine.281 Other heterocycles, e.g., uracil,282 can also be converted into hydrazines by hydroxylamine-O-sulfonic acid. 

Secondary amines do not form isoindoles. Attempts have been made to overcome this difficulty by reaction with chloramine T [279], N-chlorosuccinimide [339] or sodium hypochlorite [276,315]. 

The N-chloramines 12 are conveniently obtained by addition of aliphatic primary amines to acceptor-substituted olefins and N-chlorination of the resulting secondary amines 11 with trichloroisocyanuric acid. 

Primary, secondary, and tertiary amines can be aminated by chloramine also, but pyridine nitrogens have been aminated only by hydrovylamine-O-sulfonic acid. 

If nitration under acidic conditions could only be used for the nitration of the weakest of amine bases its use for the synthesis of secondary nitramines would be severely limited. An important discovery by Wright and co-workers " found that the nitrations of the more basic amines are strongly catalyzed by chloride ion. This is explained by the fact that chloride ion, in the form of anhydrous zinc chloride, the hydrochloride salt of the amine, or dissolved gaseous hydrogen chloride, is a source of electropositive chlorine under the oxidizing conditions of nitration and this can react with the free amine to form an intermediate chloramine. The corresponding chloramines are readily nitrated with the loss of electropositive chlorine and the formation of the secondary nitramine in a catalytic cycle (Equations 5.2, 5.3 and 5.4). The mechanism of this reaction is proposed to involve chlorine acetate as the source of electropositive chlorine but other species may play a role. The success of the reaction appears to be due to the chloramines being weaker bases than the parent amines. 

Chloramines are considered as main products secondary to hypochlorite formation. Taurine is one of the most abundant sources of free amino groups in polymorphonuclear neutrophilic leukocytes, representing approximately 50% of all low-molecular-weight amines released by PMNs (G24, Z5), and taurine chloramine is formed immediately along with MPO-mediated HOC1 synthesis ... 

Both the primary amine funtuphyllamine-A (XXVI) and the secondary base funtuphyllamine-B (XXVII) gave funtuphyllamine-C (XXVIII) on Eschweiler-Clarke methylation. The structure of funtu-phyllamine-B follows from the result of the Ruschig degradation (conversion of a primary or secondary base to a ketone via chloramine and ketimine) (19), which furnished 3 -hydroxy-5 -pregnan-20-one. 0-Acetylfuntuphyllamine-C proved to be identical with the known (20) 3 -acetoxy-20a-dimethylamino-6a-pregnane. Funtuphyllamine-B is... 

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