New One-Pot Synthesis of 4-Hydroxybenzaldehyde Derivatives and Picric Acid from 4-Hydroxyphenylglycine with HNO3/H2O

摘要

Since aromatic aldehydes are important intermediates in the chemical, pharmaceutical and cosmetic industries, easy and convenient synthetic methods to synthesize them have been pursued. Among the most widely-used methods are formylation of aromatic compounds and oxidation of primary alcohols. Previous reports describe a variety of formylation reagents, including formyl fluoride HGOF and BF3, dichloromethyl methyl ether and AlCl3, formamides and phosphorus oxychloride (Vilsme-ier-Haack reaction), Zn(CN)2 and HCl (Gatterman reaction), NaCN and super acidic conditions (F3CSO2OH-SbF5),while various oxidizing agents, such as Na2Cr2O7in water, K2Cr2O7 in DMF, CrO3 on silica gel, NCS-TEMPO, tetrapropylam-monium perruthenate (TPAP) and nitroxyl radical oxidaizing agent, have been utilized to convert primary alcohols to aldehydes.