Silica Gel-Catalyzed One-Pot Syntheses in Water and Fluorescence Properties Studies of 5-Amino-2-aryl-3H-chromeno[4,3,2-de][1,6]naphthyridine-4-carbonitriles and 5-Amino-2-aryl-3H-quinolino[4,3,2-de][1,6]naphthyridine-4-carbonitriles

Abstract

The silica gel-catalyzed synthesis of 5-amino-2-aryl-3H-chromeno[4,3,2-de][1,6]naphthyridine-4-carbonitriles and 5-amino-2-aryl-3H-quinolino[4,3,2-de][1,6]naphthyridine-4-carbonitriles were simply achieved upon the one-pot cascade reaction of malononitrile with substituted 2-hydroxyacetophenone (or 2-aminoacetophenone) and aromatic aldehyde in aqueous media. The mechanistic investigation results based on electrospray ionization mass spectrometry (ESI-MS) indicated that malononitrile displayed a dual role during this transformation. Thirteen bonds were cleaved and 12 new bonds were constructed in the formation of 5-amino-2-aryl-3H-chromeno[4,3,2-de][1,6]naphthyridine-4-carbonitriles, while only 2 H(2)O molecules were removed. The fluorescence properties screening showed five new compounds have high fluorescence quantum yields.

Electrochemical, Theoretical, and Surface Morphological Studies of Corrosion Inhibition Effect of Green Naphthyridine Derivatives on Mild Steel in Hydrochloric Acid

“…N-1, N-2, and N-3 were synthesized according to a previously reported method . The synthetic route is shown in Scheme .The compounds were recrystallized from ethanol.…”

One‐Pot Synthesis of New Chromeno[1,6]naphthyridine Derivatives Catalyzed by a Basic Ionic Liquid, [HO‐CH2‐CH2‐NH3+][HCOO−]

“…There are also few synthetic methods available in literature for the synthesis of chromeno[ 1,6 ]naphthyridines [15] . Literature survey showed us that Fe 3 O 4 @SiO 2 ‐O−B(OSO 3 H) 2 , [18] SiO 2 , [19] and Fe 3 O 4 [20] as catalysts were used for preparation of chromeno[ 1,6 ]naphthyridine derivatives. In continuation to our research on new methods in organic synthesis, [16] we developed the synthesis of chromeno[ 1,6 ]naphthyridine derivatives by one‐pot pseudo four‐component condensation of aromatic aldehydes (1 mmol), malononitrile (2 mmol), and 2 /− hydroxyacetophenone derivatives (1 mmol), using ionic liquid [HO‐CH 2 ‐CH 2 ‐NH 3 + ][HCOO − ] as catalyst (Scheme 1).…”

Evaluation of Silica-H2SO4 as an Efficient Heterogeneous Catalyst for the Synthesis of Chalcones

“…Similarly the heterogeneous catalysis is preferred over homogenous catalysis because of the work-up, economical and environmental advantages of the former. Silica-H 2 SO 4 (SSA) is a versatile, selective and a powerful catalyst that has been explored for various organic transformations, such as the synthesis of heterocyclic compounds [23,24,25,26,27], cross-aldol condensations [28], Michael additions [29], protection [30,31], deprotection [32] and oxidation reactions [33]. The major advantages of SSA include: ease of preparation, ease of removal from reaction mixtures, comparatively mild conditions as compared to H 2 SO 4 as well as NaOH.…”