Amino(diamino)phenylalkanols are semiproducts of the synthesis of some technical materials (polymers, ion-exchanger resins, dyes) [2][3][4] and biologically active substances [5].The known methods of obtaining these compounds are based on the reduction or catalytic hydrogenation of nitro(dinitro)phenylalkanols [4,[6][7][8][9], nitroarylaldehydes [8], nitroeinnamie alcohols [10], nitroolefm oxides [3,11], and aminophenylcarboxylic acids [12] or their esters [13].In the past decades, the attention of researchers was drawn to the use of readily available nitro(dinitro)phenylalkanol nitroesters, which frequently form already in the course of nitrosation of initial arylalkanols. These compounds found application as semiproducts in the synthesis of aromatic nitro compounds representing the classes of acids, aldehydes, ketones, olefins, alcohols, etc.However, the process of reduction of these nitreesters is rather insufficiently studied. A few studies reported include the hydrogenation of 13-4-nitrophenylethyl nitrate [ 14] and its reduction by hydrazine hydrate [2] to 13-4-aminophenylethanol [2, 14, 15] (in [15], neither the reducer type nor the reaction conditions and yields of amino alcohol were indicated).We have thoroughly studied the hydrogenation of ni= troesters of some 2-nitro-, 3-nitro=, 4-nitro-, and 2,4=dini-trophenylalkanols containing nitroester groups in the or-, 13-, and ~-positions with respect to the benzene ring (compounds I-VIII). The reactions were catalyzed by the readily available Raney nickel catalyst. It was established that the hydrogenation of compounds I -VIII easily proceeds in solutions of lower alcohols (methanol, ethanol) at 18-250C at atmospheric or elevated (5-30 alan) hydrogen pressure and leads to a high yield (91 -98 %) of the corresponding amino(diamino)phenylalkanols (IX-XVI). In some cases, the products can be subsequently used without additional purification; the fine syntheses may require a single recrystallization. Both processes, the nitro group reduction to amino group in the benzene ring and the hydrogenolysis of the nitroester fragment to hydroxy group and ammonia in the side chain, seem to proceed in parallel to one another.The proposed method is much simpler compared to the pathway involving the nitroester reduction by hydrazine hydrate and is especially convenient for the synthesis of (4-aminophenyl)alkanols.
598rldNi-R~ O2NC6H'~ HR _H20, -NH 3. H2NC,H,~HR ONO 2 OH