ChemInform Abstract: Reactivity of 3‐Cinnamoyl‐2‐pyrones Towards Primary Amines.

4‐hydroxy‐6‐methyl‐3‐(5‐phenyl‐2E,4E‐pentadien‐1‐oyl)‐2H‐pyran‐2‐one: Synthesis and reactivity with amines

“…After solvent evaporation and recrystallisation in ethanol, 3.05 g of (E) -4 -h y d r o x y -6 -m e t h y l -3 -( 1p h e n y l -5 -s t y r y l -4 , 5 -d i h y d r o p y r a z o l -3 -y l ) -2H-pyran-2-one 5 (82%) was obtained, mp 146 °C; 1 H nmr (deuteriochloroform): δ 2.26 (s, 3 H, 6-CH 3 ), 3.51 (dd,1 H,J = 7.4 and 18.8 Hz,3.95 (dd,1 H,J = 11.6 and 18.8 Hz,4.79 (dt,1 H,J = 7.4 and 11.6 Hz,, 6.03 (s,1 H,6.27 (dd,1 H,J = 7.4 and 15.9 Hz,6.63 (d,1 H,J = 15.9 Hz,6.89 (t,1 H,J = 7.3 Hz,7.06 (d,2 H,J = 7.9 Hz,6''),7 H,13.34 (s,1 H,; 13 C nmr (deuteriochloroform): δ 20. After solvent evaporation and recrystallisation in ethanol, 3.05 g of (E) -4 -h y d r o x y -6 -m e t h y l -3 -( 1p h e n y l -5 -s t y r y l -4 , 5 -d i h y d r o p y r a z o l -3 -y l ) -2H-pyran-2-one 5 (82%) was obtained, mp 146 °C; 1 H nmr (deuteriochloroform): δ 2.26 (s, 3 H, 6-CH 3 ), 3.51 (dd,1 H,J = 7.4 and 18.8 Hz,3.95 (dd,1 H,J = 11.6 and 18.8 Hz,4.79 (dt,1 H,J = 7.4 and 11.6 Hz,, 6.03 (s,1 H,6.27 (dd,1 H,J = 7.4 and 15.9 Hz,6.63 (d,1 H,J = 15.9 Hz,6.89 (t,1 H,J = 7.3 Hz,7.06 ...…”

“…Reactions of aromatic aldehydes with 3-acetyl-4hydroxy-6-methylpyran-2-one 1 (DHA) and of the obtained compounds [3-(3-aryl-2E-p r o p e n -1 -o y l ) -4h y d r o x y -6 -m e t h y l -2H-pyran-2-one] with amines have been the subject of some research groups [1][2][3][4][5][6]. Following our work on this field, we report here reactions of 1 with cinnamaldehyde and of the obtained product 2 with amines and hydrazine derivatives.…”