Synthesis
The catalytic reduction of 4-aldehyde nitrobenzene to 4-Aminobenzyl alcohol by a semi-sandwich ruthenium complex 2a is as follows: Synthesis of the semi-sandwich ruthenium complex with a 2,6-dithionone-substituted pyridine coordination compound 2a: At 25 °C, 0.05 mmol of [(CymeneRuCl2)2] and 0.1 mmol of 2,6-dimethylimidazolium-substituted pyridine were weighed into a Schlenk reaction tube, followed by the addition of 5 mL of DCM. The mixture was stirred for 16 hours under nitrogen protection. After the reaction was complete, the solution was filtered, the solvent was removed by rotary evaporation, 2 mL of CH3OH was added to dissolve the solid, and then an aqueous solution of saturated KPF6 (containing 0.25 mmol of KPF6) was added. A solid was immediately produced. The solid was washed with a small amount of water and diethyl ether to give 58 mg of a yellow-brown solid, with a yield of 71%.
In an air atmosphere, a polytetrafluoroethylene magnetic particle was placed in a reaction tube. 7.5 × 10⁻⁴ mmol of the semi-sandwich ruthenium coordination compound 2a was added, along with 0.3 mmol of 4-aldehyde nitrobenzene, 0.0375 ml of CH₃CN, 1.5 ml of water, 1.3 mmol of NH₃BH₃, and 0.021 mmol of CTAB. The mixture was stirred at 80 °C for 10 hours under vacuum. After the reaction was complete, the reaction solution was transferred to a separatory funnel and extracted three times with 1 ml of ethyl acetate each time. Gas chromatography-mass spectrometry (GC-MS) analysis yielded 4-Aminobenzyl alcohol (99.2% yield).
Uses
4-Aminobenzyl alcohol is used in the synthesis of 4-{N-[1-(4,4-dimethyl-2,6-dioxocyclohexylidene)-3-methylbutylamino}benzyl ester. It is also used as an intermediate in organic synthesis and pharmaceutical products.
