利用硝酰氯或硝酸酯进行硝化反应

NO₂Cl（硝酰氯）以前是由发烟硝酸和氯磺酸制得，由于这个方法不方便以及危险性大，另一个替代方法是 NaNO₃/TMSCl/AlCl₃体系【Olah, G. A; Ramaiah, G, Synthesis,1994, 468.】。NaNO₃ 和TMSCl 反应生成硝酰氯，然后再AlCl₃ 的作用下经过类似F-C反应的亲电取代过程得到硝化物, NaNO₃也可用KNO₃代替。这个硝化反应条件很温和，选择性很好，如果用其他硝化方法得到的选择性差，不妨试试这个硝化条件，其缺点是有时转化率不高。

To a suspension of KNO₃ (60.6 g, 0.6 mol) in CHCl₃ (500 mL) wasadded TMSCl (102 mL, 0.8mol) and carbonic acid 2,4-diisopropyl-phenyl esterisopropyl ester (105.6 g,0.4 mol) successively at 0^oC, the mixture was stirred for 0.5hour.  Then AlCl₃ (160 g, 1.2 mol) was added in one portionat 0 ^oC.  The mixture wasstirred for another 2 hours.  TLC showedmost of the starting material was consumed and the product was present.  The resulting mixture was poured intoice-water, extracted with CHCl₃. The combined organic layers were washed with Sat.NaHCO₃solution, brine successively, dried over Na₂SO₄ andevaporated under reduced pressure to give the crude product as an oil. To thecrude product was added 100 mL petroleum ether, the desired compound wasrecrystallized from the ether in the bath of dry ice-acetone, which wasfiltered and washed with petroleum ether to give the desired product as a paleyellow solid (27.2 g,22%).

硝酸酯，包括BuONO₂/Nafion-H,MeONO₂/BF₃, Me₃SiONO₂等，作为硝化试剂，能使活化的苯环发生硝化。

Asolutuion of 1, 2, 3, 4-tetramethylbenzene (1.34 g, 10 mmol) in nitromethane (20 mL) was addedmethyl nitrate (2.31 g,30 mmol).  The mixture was stirred at 25^oCand saturated with boron trifluoride gas. The mixture was stirred for 1 h then washedwith Sat.NaHCO₃ solution, extracted with CH₂Cl₂.  The combined organic layers were evaporatedunder reduced pressure, the residue was purified by column chromatography togive the product (1.62 g,90%).

【Olah, G. A; Lin, H.C. Synthesis, 1973, 488.】