Safrole as Starting Material for the Synthesis of 7-Metoxy-3',4'-Methylenedioxy Isoflavanone

Synthesis of a New α-Azidomethyl Styrene from Safrole via a Dearomative Rearrangement

“…Found: 320[M − 2], 322[M], 324[M + 2]. The spectroscopic data are in accordance with those reported in the literature [ 29 ].…”

“…Therefore, we conducted a small study to validate that statement. Herein, it was found that, using 1,2-dichloroethane (DCE) as the solvent during the bromination step, the reaction was deemed complete (by 1 H NMR) after only 20 min at room temperature [ 29 ], albeit the 2a/2b ratio was 1:1.2. However, when the reaction was run at 0 °C, the 2a/2b ratio changed to 1:1.75, in favor of the rearrangement adduct 2b , but the reaction time increased to 1 h. Dichloromethane and chloroform were also effective solvents providing quantitative yields after 1 h. The ratios of the products 2a and 2b using those solvents were 1:1.43 and 1:1.38, respectively ( Scheme 1 ).…”

“…Compounds 2a and 2b were synthesized via a modification of procedures described in the literature [ 25 , 29 ]: To a 100 mL round-bottomed flask, equipped with a stir bar, was added safrole (3.3 mmol, 1.0 equiv., 0.49 mL) and DCE (17 mL) at room temperature under air. The mixture was cooled down to 0 °C (ice bath), followed by dropwise addition of Br 2 (3.6 mmol, 0.18 mL, 1.1 equiv.)…”