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硝基化合物一般不用氢化锂铝(LAH)还原，因为氢化锂铝(LAH)无法将硝基还原彻底，从而得到混合物， 但对于不饱和的共轭硝基化合物则可通过氢化锂铝(LAH) 还原或NaBH4-Lewis酸的方法进行还原得到饱和的胺。
To a slurry of LiAlH4 (15.0 g, 0.395 mole) and anhydrous ether (500 mL) in a 5 liter, 3-necked flask fitted with a condenser, mechanical stirrer and dropping funnel was added the starting material (20.0 g, 0.084 mol) dissolved in 2 liters of ether. The addition was made over a period of about 4 hours while refluxing the ether slurry. When the addition was completed, refluxing was continued for an additional 1 to 2 hours. After the addition of diatomaceous earth (20 g) and then water (70 mL) slowly, dropwise, with cooling in an ice bath, the supernatant ether was decanted, the salts were washed with fresh ether several times
followed by decantation and finally filtration. The solvent was removed by distillation and more thoroughly on a rotary evaporator. Cooling in an ice bath gave 15.91 g (90% yield) of the desired product as a slightly yellow solid, m.p., 45°C. High vacuum distillation gave an analytical sample.
Boron trifluoride etherate (17.7 g) was added under nitrogen with ice-cooling to sodium borohydride (3.94 g, 0.104 mol) suspended in tetrahydrofuran (150 mL). After stirring at room temperature for fifteen minutes, the starting material (5.78 g, 0.208 mol), dissolved in tetrahydrofuran (80 mL) was added dropwise. The mixture was refluxed overnight, quenched by the addition of ice-water, acidified with 5M hydrochloric acid and refluxed for a further two hours. The aqueous layer was washed with ether and the amine liberated by the addition of ammonia solution which was extracted into dichloromethane. The extracts were
washed with water, dried and evaporated to give pure product as an oil.
To a suspension of 3-(p-nitrobenzyl)-7-benzyladenine bromaide (2.5 mmol) and sodium dithionite (1.74 g, 10 mmol) in EtOH (100 mL) is added 0.2 N aq. NaOH (100 mL, 20 mmol). The mixture is stirred at 40°C for 24 h. After cooling to room temperature, the solution is concentrated under reduced pressure to a volume of 70 mL. The precipitate obtained is filtered with suction, washed water (2×25 mL) and then dried in vacuo at 100°C in 65%yield. Analytical samples of 7-benzyladenine are obtained by recrystallization in water/EtOH.
【 Synthesis, 1988, 2, 154-155】
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