Amines reactions with adds

Reduction of a nitro compound to a primary amine. In a 50 ml. round-bottomed or conical flask fitted with a reflux condenser, place 1 g. of the nitro compound and 2 g. of granulated tin. Measure out 10 ml. of concentrated hydrochloric acid and add it in three equal portions to the mixtiue shake thoroughly after each addition. When the vigorous reaction subsides, heat under reflux on a water bath until the nitro compound has completely reacted (20-30 minutes). Shake the reaction mixture from time to time if the nitro compound appears to be very insoluble, add 5 ml. of alcohol. Cool the reaction mixture, and add 20-40 per cent, sodium hydroxide solution imtil the precipitate of tin hydroxide dissolves. Extract the resulting amine from the cooled solution with ether, and remove the ether by distillation. Examine the residue with regard to its solubility in 5 per cent, hydrochloric acid and its reaction with acetyl chloride or benzene-sulphonyl chloride. 

Reactions with Ammonia and Amines. Acetaldehyde readily adds ammonia to form acetaldehyde—ammonia. Diethyl amine [109-87-7] is obtained when acetaldehyde is added to a saturated aqueous or alcohoHc solution of ammonia and the mixture is heated to 50—75°C in the presence of a nickel catalyst and hydrogen at 1.2 MPa (12 atm). Pyridine [110-86-1] and pyridine derivatives are made from paraldehyde and aqueous ammonia in the presence of a catalyst at elevated temperatures (62) acetaldehyde may also be used but the yields of pyridine are generally lower than when paraldehyde is the starting material. The vapor-phase reaction of formaldehyde, acetaldehyde, and ammonia at 360°C over oxide catalyst was studied a 49% yield of pyridine and picolines was obtained using an activated siHca—alumina catalyst (63). Brown polymers result when acetaldehyde reacts with ammonia or amines at a pH of 6—7 and temperature of 3—25°C (64). Primary amines and acetaldehyde condense to give Schiff bases CH2CH=NR. The Schiff base reverts to the starting materials in the presence of acids. 

Dicyanoacetylene, 2-hiitynedinitri1e, is obtained from dimethyl acetylenedicarboxylate by ammonolysis to the diamide, which is dehydrated with phosphoms pentoxide (44). It bums in oxygen to give a flame with a temperature of 5260 K, the hottest flame temperature known (45). Alcohols and amines add readily to its acetylenic bond (46). It is a powerhil dienophile in the Diels-Alder reaction it adds to many dienes at room temperature, and at 180°C actually adds 1,4- to benzene to give the bicyclo adduct (7) [18341 -68-9] C QHgN2 (47). 

M or Tl catalyzed tetfamedzallon d trtanerization of acetylene and reactions with alcohols, amines, caiboxyNe adds, thiols. 

Trichloroacetic acid behaves somewhat similarly in that protonation of the enamine occurs l7J7d). Subsequent decarboxylation of the trichloro-acetate gives trichloromethyl anion, which adds to the iminium cation to give the trichloromethyl amine derivative. Thus the enamine (113) undergoes reaction with trichloroacetic acid to give N-[l-(trichloromethyl)cyclo-hexyl]-morpholine (8). The latter compound undergoes rearrangement on... 

Grignard reagents do not add directly to enamines, but their reactions with the corresponding imonium salts readily furnish tertiary amines (225,526). The reductive removal of halogen has been observed in the addition of Grignard reagents to a-bromoimonium salts (527). 

The ketocarbene 4 that is generated by loss of Na from the a-diazo ketone, and that has an electron-sextet, rearranges to the more stable ketene 2 by a nucleophilic 1,2-shift of substituent R. The ketene thus formed corresponds to the isocyanate product of the related Curtius reaction. The ketene can further react with nucleophilic agents, that add to the C=0-double bond. For example by reaction with water a carboxylic acid 3 is formed, while from reaction with an alcohol R -OH an ester 5 is obtained directly. The reaction with ammonia or an amine R -NHa leads to formation of a carboxylic amide 6 or 7 ... 

Polyazetidine prepolymer may be cross-linked in aqueous solution by reaction with amine, thiol, hydroxyl, carboxylic add or other polyazetidine groups. Cross-linking occurs upon water removal, heating or by changing to a basic pH. The immobilised cell/polymer composition may be prepared in the form of membranes, fibres, tubes or beads. 

Amines, thiols, eOH (p. 226), etc., will also add to the 0-carbon atom of 0-unsaturated carbonyl compounds and esters, but the most important reactions of C=C—C=0 systems are in Michael reactions with carbanions reactions in which carbon-carbon bonds are formed. A good example is the synthesis of l,l-dimethylcyclohexan-3,5-dione (dimedone, 100) starting from 2-methylpent-2-ene-4-one (mesityl oxide, 101) and the carbanion 0CH(CO2Et)2 ... 

Anilinediphenylamine phosphate 1 ml aniline + 1 g diphenylamine in 100 ml acetone. Add 10 ml 85% orthophosphoric acid Dip Reaction with aromatic amine in hot acid... 

Amine 212 was also coupled with peptides [233], acetic anhydride [215, 234], dinitrobenzoyl chloride [235] or a ferrocene carboxylic add chloride [215, 236] in good yields. Reaction with dinitrochlorobenzene [237] or dinitrofluorobenzene... 

The scheme used to produce a somewhat more complex 5-a-reductase inhibitor relies on a chiral auxiliary to yield the final product as a single enantiomer. The first step in a sequence similar to that above starts with the reaction of bromotetralone (23-1) with R-a-phenethyl amine (23-2) to afford the enamine (23-3). Reaction with methyl iodide adds the methyl group at what will be a steroid-like AB ring junction... 

The hydroxyquinoline (39-2) provides the starting material for a quinolone that incorporates a hydrazine function. Reaction of (39-2) with 2,4-dintrophenyl O-hydroxylamine ether (41-1) in the presence of potassium carbonate leads to a scission of the weak N-O hydroxylamine bond by the transient anion from the quinolone the excellent leaving character of 2,4-dinitrophenoxide adds the driving force for the overall reaction, resulting in alkylation on nitrogen to form the hydrazine (41-2). The primary amine is then converted to the formamide (41-3) by reaction with the mixed acetic-formic anhydride. Alkylation of that intermediate with methyl iodide followed by removal of the formamide affords the monomethylated derivative (41-4). Chlorine at the 7 position is then displaced by A-methylpiperazine and the product saponified. There is thus obtained amifloxacin (41-6) [48]. 

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