Amines bromo acid bromides

A related synthesis produces indolones by a different Friedel-Crafts route. The Stolle synthesis reacts with a secondary aryl amine such as diphenylamine with an a-chloro acid chloride or an a-bromo acid bromide to give an a-bromoamide (such as 315) or an a-chloroamide. An early version of the reaction used oxalyl chloride, but a more typical example is the reaction of 2-bromopropanoyl bromide with 314 to give 315. Friedel-Crafts cyclization (with AICI3) led to the indolone 316.1 ... 

Finally, Lecomte and coworkers reported the synthesis of mikto-arm star-shaped aliphatic polyesters by implementing a strategy based on click chemistry (Fig. 36) [162]. Firstly, the polymerization of sCL was initiated by a diol bearing an alkyne function. The chain-ends were protected from any further undesired reaction by the esterification reaction with acetyl chloride. The alkyne was then reacted with 3-azidopropan-l-ol. The hydroxyl function located at the middle of the chain was then used to initiate the ROP of sCL and y-bromo-s-caprolactone. Finally, pendant bromides were reacted successfully with sodium azide and then with N, N-dimethylprop-2-yn-l-amine to obtain pendant amines. Under acidic conditions, pendant amines were protonated and the polymer turned out to exhibit amphiphilic properties. 

In one synthetic approach (Veld 1990, 1992), alanine is first converted to the bromo derivative via the reaction of the diazonium salt of the amine with hydrogen bromide. In the next step the acid functionality is activated by converting it to the acid chloride using thionyl chloride. The activated acid is condensed with a protected a-amino acid to yield the dipeptide intermediate which is then cyclized by heating in presence of Celite (ion exchange resin) to yield the final product. However, the overall yield of this reaction is fairly low. A more elegant approach is shown in Scheme 5. In this approach, an a-amino acid wth a protected side chain (e.g., e-Z-lysine) is reacted with 2-bromo-propionyl bromide under Schotten-Bauman condidons (Fischer 1908) to yield the intermediate 5a, which is then cyclized under basic conditions to the depsipeptide 5b. 

In the preparation of bromo compounds by the Sandmeyer reaction, the amine is generally diazotised in sulphuric acid solution (or in hydrobromic acid solution), and the resulting aryldiazonium sulphate (or bromide) is treated with a solution of cuprous bromide in excess of hydrobromic acid the addition... 

Bromo-6,7,8,9-tetrahydro-l//-3-benzazepin-2-amine(6) with thiocyanate ion undergoes substitution of bromide to give the thiocyanatotetrahydro-l//-3-benzazepine 7.105 Attempts to replace bromide by azide ion failed, as did diazotization of the amine group with sodium nitrite in 6 M sulfuric acid. Oddly, treatment of the aminobromo compound with sodium borohydride in methanol results not in reduction, but in methoxy-debromination to give the 2-methoxy derivative which, on the basis of HNMR spectral data, is best represented as the 2-imino tautomer 8. 

Benzene- 1,2-diacetonitriles e.g. 19, in the presence of hydrogen bromide in acetic acid, or in diethyl ether, cyclize to 4-bromo-l //-3-benzazepin-2-amines, e.g. 20a.41,42 l//-Naphtho[2,3-t/]azepines, e.g. 22a, are prepared in a similar manner from naphthalene-2,3-diacetonitriles, e.g. 21.41 Replacement of hydrogen bromide by hydrogen iodide yields the corresponding 4-iodo derivatives, e.g. 20b and 22b. 

The isomeric naphthalene-1,2-diacetonitrile (23) behaves differently in that with hydrogen bromide in acetic acid a mixture of 4-bromo-l //-naphtho[2,l-r/]azepin-2-amine (24) and 4-bromo-l//-naphtho[l, 2-r/]azepin-2-amine (25) is formed, from which only one isomer (32% mp 232-238 °C dec.), of undetermined structure, was isolated and purified.41... 

A mixture of (triisopropyl phosphito)copper(I) bromide (17.6 g, 0.05 mol) and l-bromo-2,2-diphenylethylene (9.1 g, 0.035 mol) was heated at 200°C for 1 h under a nitrogen atmosphere in a flask equipped with a Vigreaux column topped by a Dean-Stark trap. The alkyl halide produced in the reaction was collected in the trap. After cooling, the reaction mixture was poured into toluene (60 ml), and ethylenedi-amine was added (5 ml). After filtering and washing the precipitate with toluene, the combined toluene solutions were washed with 10% hydrochloric acid (10 ml) and water (10 ml), dried over magnesium... 

Currently available BAS include cholestyramine, colestipol and colesevelam hydrochloride (colestimide). Cholestyramine comprises a long-chain polymer of styrene with divinylbenzene trimethylbenzylammonium groups, whereas colestipol is a long-chain polymer of l-chloro-2,3-epoxypropane with diethylenetriamine. Colesevelam HCl is poly(allylamine hydrochloride) cross-linked with epichlorohydrin and alkylated with 1-bromodecane and 6-bromo-hexyl-trimethylammonium bromide. Bile-acid binding is enhanced and stabilised in the latter compound by long hydrophobic sidechains, increased density of primary amines, and quaternary amine sidechains. For this reason, colesevelam HCl exhibits increased affinity, specificity and capacity to bind bile acids compared with the other BAS. Colesevelam HCl also binds dihydroxy and trihydroxy bile acids with equal affinity, contrasting with cholestyramine and colestipol that preferentially bind dihydroxy bile acids (CDCA and deoxycholic acid). The latter BAS can lead to an imbalance towards trihydroxy bile acids and a more hydrophilic bile-acid pool. 

In very reactive halogen derivatives such as a-bromo ketones [234] and a-bromothiophene [235] the halogens are replaced by hydrogen with hydrogen bromide in acetic acid provided phenol is added to react with the evolved bromine and to affect favorably the equilibrium of the reversible reaction. Hydrogen bromide in acetic acid also reduces azides to amines [232],... 

For the preparation of chlorides or bromides, the diazonium salt is decomposed with a solution of cuprous chloride or bromide in the corresponding halogen acid (Sandmeyer reaction). It is possible to prepare the aryl bromide from the diazonium chloride or sulfate. A variation Involves the use of copper powder and a mineral acid for the decomposition step (Gattermann reaction). Both procedures are illustrated by the syntheses of the isomeric bromotoluenes and chlorotoluenes. The usual conditions of the Sandmeyer reaction fail in the preparation of the chloro- and bromo-phenanthrenes. However, these compounds can be successfully obtained by the interaction of the diazonium compound with mercuric and potassium halides (Schwechten procedure). Another procedure for formation of aryl bromides involves treatment of the amine hydrobromide with nitrogen trioxide in the presence of excess 40% hydro-bromic acid. The Intermediate diazonium perbromide is then decomposed by heat. ... 

Smooth conversion of azides to amines was achieved by using hydrogen bromide in acetic acid solution . The reduction is, when possible, accompanied by bromination by the liberated bromine. The bromination can be prevented by addition of a bromine acceptor. 2-Azido-5-nitrobiphenyl (23) thus yielded 2-amino-3-bromo-5-nitrobiphenyl (24), but in the presence of phenol the product was 2-amino-5-nitrobiphenyl (25) . The method has also been used with amino acids, acetone serving as a bromine acceptor . 

A noteworthy difference is observed in the condensation of thiosemicarbazide with aromatic a-halocarbonyl compounds in comparison to aliphatic a-halocarbonyl compounds. It has been found26 that the reaction of phenacyl bromide with thiosemicarbazide furnishes 5-phenyl-1,3,4-thiadiazin-2-amine together with a small amount of 5-phenylthiazolc-2-hydrazine, Similarly, the reactions of thiosemicarbazide with 2-bromo-l,2-diphenylethan-l-one,7 8,41 2-bro-mo-l-phenylpropan-l-one,10,41 and 2-bromo-l-phenylbutan-l-one 10,41 in ethanolic solution give 1,3,4-thiadizines. However, the main products are the thiazole-2-hydrazine derivatives (cf. Houben-Weyl, Vol. E8b, p 72ff). The addition of an equimolar amount of 48% hydro-bromic acid results in the exclusive formation of the 1,3,4-thiadiazines 2 a, c, and d. When the condensations of thiosemicarbazide with 2-bromo-l,2-diphenylethan-l-one, 2-bromo-1-phenylpropan-l-one or 2-bromo-l-phenylbutan-l-one are performed in ethanol at room temperature, the S-(oxoalkyl)-isothiosemicarbazide hydrobromides are formed as open-chain intermediates and also undergo cyclization in ethanol upon addition of an equimolar amount of 48% hydrobromic acid to furnish 2 a, c, and d. 

Styrene (St) (Aldrich, 99%) was used as received and /-butyl aciylate (/BA) (Aldrich, 99%) was passed through a column filled with basic alumina. Tris(2-dimethylaminoethyl)amine (MceTREN, 99 %) and tris(2-pyridylmethyl)amine (TPMA, 99 %) are commercially available from ATRP Solutions Inc (www.atrpsolutions.com). ATHPpare resin (ATRP Solutions Inc.), diethyl 2-bromo-2-methylmalonate (DEBMM) (Aldrich, 98%), copper(ll) bromide (Aldrich, 99%), tin(ll) 2-ethylhexanoate (Sn(EH)2) (Aldrich, 95%), N,N-dimethylformamide (DMF) (Aldrich, 99%), methylene chloride (Fisher Scientific), trifluoroacetic acid (TFA) (Aldrich, 99%) and 2,2 -azo-bis(isobutyronitrile) (AIBN) (Aldrich, 99%) were used as received. Fc203 particles (size < 50 nm) were purchased form Aldrich. 

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