By reduction of nitriles

We ve already seen in Sections 20.7 and 21.7 how amines can be prepared by reduction of nitriles and amides with LiAlH4. The two-step sequence of 5 2 displacement with C followed by reduction thus converts an alkyl halide into a primary alkylamine having one more carbon atom. Amide reduction converts carboxylic acids and their derivatives into amines with the same number of carbon atoms. 

The key intermediate 25 was prepared efficiently from aldehyde 23, obtained by reduction of nitrile 22 with Dibal-H. Treatment of 23 with the lithium salt of frans-diethyl cinnamylphosphonate furnishes compound 24 in 75 % yield and with a 20 1 ratio of E Z olefin stereoisomers. The stage is now set for the final and crucial operations to complete the molecular skeletons of endiandric acids A and B. 

Just as amines are easily obtained by reduction of nitriles with sodium amalgam or sodium and alcohol, so this reaction can be carried out electrolytically (p. 121). 

The amine group in primary amines can be replaced by halogen by warming the benzoyl derivative with phosphorus pentachloride or phosphorus pentabromide. Oftentimes, the separation of the halide from the benzonitrile, which is also formed, is troublesome. The process has been applied mostly to high-moIecuIar-weight amines obtained by the Hofmann degradation of acid amides or by reduction of nitriles." Diamines lead to dihalogen derivatives." If N-benzoyl piperidines are treated, substituted pentamethylene halides are formed. An example is the synthesis of pentamethylene bromide by the action of phosphorus pentabromide on N-benzoyl piperidine (72%). ... 

Cyclopropylimines are usually generated by reduction of nitriles or condensation of carbonyl compounds with amines. An alternative to this process involves the generation of cyclopropylinunoni-um salts such as (209) at room temperature from cyanohydrin equivalent (208 Scheme 49). ... 

Zakharkin, L.L, and Khorlina, I.M., Preparation of aldehydes by reduction of nitriles with diisobutyl-aluminium hydride, Dokl. Akad. Nauk SSSR, Ser. Khim., 116,422,1957 Chem. Abstr, 52, 8040f. 1958. 

By reduction of nitriles, oximes, and amides (discussed in Section 20.4D) (1) LIAIH4, EtjO... 

Amides may also be prepared by reduction of nitriles to amines followed by acylation. See section 103 (Amines from Nitriles)... 

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