Sulfuric Acid → HCID 57440927, compound

Participants

Reaction Conditions

Reaction Steps

This quinone can be obtained by following the procedure describe in Example 36, Step 1 to 3, or by the using the following procedure: to a 0° C. solution of 118 mL of concentrated sulphuric acid in 1.0 L of water was added drop wise a solution prepared as follows: 65 g of (2E)-3-(2-amino-4-chlorophenyl)-2-(4-bromophenyl)acrylic acid from Step 2 in 1 L of water followed by the addition of 11 g of NaOH, stirring for 10 minutes at 0° C., addition of NaNO2 (15 g) and stirring of the resulting solution at 0° C. for 20 minutes. After 30 minutes, sulfamic acid (12.5 g) was added to this mixture and after the gaz evolution seized, 1.3 L of acetone was added and the solution was stirred at 0° C. for 10 minutes. This mixture was then added to a solution of ferrocene (6.9 g) in 480 mL of acetone resulting in the formation of a green precipitate. After stirring for 20 minutes, water (2.0 L) was added, the solid was filtered and the 6-bromo-3-chlorophenanthrene-9-carboxylic acid was obtained and allowed to air dry. This crude phenanthrene was placed in 2.0 L of acetic acid followed by the addition of 54 g of CrO3. The reaction was placed at 110° C. and after stirring for 1 hr, 18 g of CrO3 were added. The reaction was monitored by TLC and 18 g of CrO3 were added every hour for 3 hours where 100% conversion was observed by 1H NMR. The mixture was cooled to room temperature, diluted in water (2.0 L), filtered and washed with water (1.0 L) to afford, after drying, 37 g of 3-Bromo-6-chlorophenanthrene-9,10-dione as a yellow solid.

Provenance & Evidence