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Most common imides are prepared by heating dicarboxylic acids or their anhydrides and ammonia or primary amines. The result is a condensation reaction: [5] (RCO) 2 O + R′NH 2 → (RCO) 2 NR′ + H 2 O. These reactions proceed via the intermediacy of amides. The intramolecular reaction of a carboxylic acid with an amide is far faster than the ...
Treatment of the resulting compound with ammonia then completes the conversion to the amidine. [1] Instead of using a Bronsted acid, Lewis acids such as aluminium trichloride promote the direct amination of nitriles, [2] or, in certain exceptional cases, of amides. [3] Dimethylformamide acetal reacts with primary amines to give amidines: [4]
The general structure of an imine. In organic chemistry, an imine (/ ɪ ˈ m iː n / or / ˈ ɪ m ɪ n /) is a functional group or organic compound containing a carbon–nitrogen double bond (C=N). The nitrogen atom can be attached to a hydrogen or an organic group (R). The carbon atom has two additional single bonds.
The reaction is acid catalyzed and the reaction type is nucleophilic addition of the amine to the carbonyl compound followed by transfer of a proton from nitrogen to oxygen to a stable hemiaminal or carbinolamine. With primary amines, water is lost in an elimination reaction to an imine. With aryl amines, especially stable Schiff bases are formed.
Primary amines are usually not used for enamine synthesis due to the preferential formation of the more thermodynamically stable imine species. [11] Methyl ketone self-condensation is a side-reaction which can be avoided through the addition of TiCl 4 [ 12 ] into the reaction mixture (to act as a water scavenger ).
Amidoximes are oximes of amides (R 1 C(=O)NR 2 R 3) with general structure R 1 C(=NOH)NR 2 R 3. Oximes are usually generated by the reaction of hydroxylamine with aldehydes (R−CH=O) or ketones (RR’C=O). The term oxime dates back to the 19th century, a combination of the words oxygen and imine. [1]
Compared to amines, amides are very weak bases. While the conjugate acid of an amine has a pK a of about 9.5, the conjugate acid of an amide has a pK a around −0.5. Therefore, compared to amines, amides do not have acid–base properties that are as noticeable in water. This relative lack of basicity is explained by the withdrawing of ...
In organic chemistry, a hemiaminal (also carbinolamine) is a functional group or type of chemical compound that has a hydroxyl group and an amine attached to the same carbon atom: −C(OH)(NR 2)−. R can be hydrogen or an alkyl group. Hemiaminals are intermediates in imine formation from an amine and a carbonyl by alkylimino-de-oxo ...