5423-67-6Relevant articles and documents
Synthesis and structures of 3-hydroxy-6-(R-phenylazo)-7,8-benzo-1,2,3,4- tetrahydroquinolines as products of analytical test reactions for nitrite and nitrate anions
Ostrovskaya,Tsygankov,Nefedov,Prokopenko,Reshetnyak
, p. 1066 - 1070 (2006)
An improved procedure was proposed for the synthesis of 3-hydroxy-7,8-benzo-1,2,3,4-tetrahydroquinoline, which is used as a reagent for the analytical test reaction for nitrate and nitrite anions based on azo coupling with diazo compounds. 3-Hydroxy-6-(R-phenylazo)-7,8-benzo-1,2,3,4- tetrahydroquinolines (R = 2-COOH, 4-COOH, or 4-SO3H) were synthesized by azo coupling reactions in 65-70% yields. The structures of these compounds were confirmed by elemental analysis, 1H NMR and IR spectroscopy, and X-ray diffraction. Based on the X-ray data, the bathochromic shift in the UV spectrum of the o-carboxy isomer compared to the p-carboxy isomer (Δλmax = 50 nm) is attributed to a strong intramolecular hydrogen bond.