Unsaturated 4H-1,3-oxazines (review)

Hydroxyapatite catalyzed cyclization of aryl enones: Solvent-free efficient synthesis of some 4-aryl-5,6-dihydro- 6-(substituted phenyl)-4H-1,3-oxazine-2-amines

“…An appropriate equi-molar quantities of chalcones (2 mmol), urea (2 mmol) and 0.2 g of hydroxyapatite were taken in a 50 cm 3 beaker, closed with the lid. This mixture was subjected to microwave irradiation for 2-4 minutes at 650W (Scheme 1) (Samsung, Microwave Oven, 100-700W).…”

“…Depend upon the relative position of these tow atoms and the double bond, these molecule exists many isomeric structures such as 1, 2 or 1, 3 or 1, 4 oxazines [3]. These oxazines were medicinally important due to the presence of oxygen, nitrogen heteroatoms along with a double bonds in their structural moieties [4].…”

Synthesis of 5‐Halo‐4H‐1,3‐oxazine‐6‐amines by a Copper‐Mediated Domino Reaction

“…Recently, this kind of oxidative coupling reaction to terminal alkynes has been highlighted. [7] In addition, 1,3-oxazines are a well-known structural motif for biologically active substances [8] and have a wide range of therapeutic use. Compounds with such a structure exhibit antifungal, [9] antibiotic, [9][10][11] antiviral, [12] and antitumor [13] properties.…”

Aryl α, β-Unsaturated Ketones as Efficient Precursor for Synthesis of Unsaturated 1,3-oxazine-2-amines under Solvent-free Conditions

“…The unsaturated 1,3-oxazine-2-amine and their derivatives are an important six membered heterocyclics possess one nitrogen, oxygen atom, one double bond and the amine group bonded in 2 nd position carbon from oxygen (Banarjee et al, 2009;Yakovlev et al, 1994;Jacob et al, 1986). These oxazines are exists more than ten isomeric structures depend upon the relative position of unsaturation and the hetero atoms (Manjula et al, 2009).…”