Sulfuric Acid → HCID 70926597, compound

HRID 572948Notes

Reaction equation

[CH3:1][C:2]1([CH3:18])[C:6]2[CH2:7][CH2:8][C:9]3[CH:10]=[N:11][CH:12]=[N:13][C:14]=3[C:5]=2[C:4]([CH3:16])([CH3:15])[CH:3]1[CH3:17].S(=O)(=O)(O)O>C1(C)C=CC=CC=1>[CH3:1][C:2]1([CH3:18])[C:6]2[CH2:7][CH2:8][C:9]3[CH:10]=[N:11][CH:12]=[N:13][C:14]=3[C:5]=2[C:4]([CH3:16])([CH3:15])[CH:3]1[CH3:17].[CH3:1][C:2]1([CH3:18])[C:6]2=[CH:7][CH:8]=[C:9]3[C:14]([N:13]=[CH:12][N:11]=[CH:10]3)=[C:5]2[C:4]([CH3:16])([CH3:15])[CH:3]1[CH3:17]

Participants

Conditions

Temperature: 220 °C

Procedure

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.

Workup

temperaturecooled to 80° C
customThe organic layer was separated
washwashed twice with brine (2 L), twice with aqueous sodium hydroxide (NaOH) (25%, 2 L)
distillationThe crude product was purified by vacuum distillation

Sources & evidence

ORD record: ord-8dc290340344412ea25c8dee6e6311bf
Source dataset: uspto-grants-2015_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09029535B2

Reaction notes

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