Sulfuric Acid → HCID 70926597, compound

Participants

Reaction Conditions

Reaction Steps

7,7,8,9,9-Pentamethyl-6,7,8,9-tetrahydro-5H-cyclopenta[H]quinazoline was prepared as described in EXAMPLE I of U.S. Publication No. 2012/0207697 and in EXAMPLE I of U.S. Publication No. 2012/0277325. A 3-L reaction vessel was charged with 7,7,8,9,9-pentamethyl-6,7,8,9-tetrahydro-5H-cyclopenta[H]quinazoline (1 Kg) and sulfuric acid (H2SO4) (100 g). The reaction mixture was heated to 220° C. for 12 hours and then cooled to 80° C. The resulting mixture was diluted with toluene (1 L). The organic layer was separated and washed twice with brine (2 L), twice with aqueous sodium hydroxide (NaOH) (25%, 2 L) and then twice with brine (2 L). The crude product was purified by vacuum distillation to afford 7,7,8,9,9-Pentamethyl-8,9-dihydro-7H-cyclopenta[H]quinazoline (992 g) having a boiling point of 160° C. at 1.0 mmHg. Further recrystallization from ethanol afforded a solid with a melting point of 84.0° C.

Provenance & Evidence