2,5-Di-tert-butyl-1,4-benzoquinone

Yellow to golden crystalline powder

General procedure: To a solution of dihydroxy arene (0.34 mmol) and 2a (1.98 mg, 0.0034 mmol) in THF (1.0 mL) was added H2O2 (30percent aq, 50.0 mL, 0.44 mmol) at 0 C. After 5 min the starting material had completelyoxidized to the quinone product. The quinone product wasthen extracted by ether or dichloromethane, dried over anhydrous Na2SO4, and concentrated under reduced pressure to afford thedesired product. Pleasingly, the resulted quinone products werepure enough and there is no necessity for column chromatographyin most of the cases.General procedure: A solution of CAN (0.056 g, 0.102 mmoles) and sodium bromate (0.780 g, 5.17 mmoles) in H2O (3 mL) was added slowly to vigorously stirred anhydrous silica gel (5 g) that was contained in a 100 mLround-bottom flask containing a magnetic stirring bar and fitted with a rubber septum. After complete addition of the aqueous solution, stirring was continued until a free-flowing powder was obtained.CH2Cl2 (25 mL) was then added to the flask and a solution of hydroquinone 1A (220.23 mg, 2.0 mmol), in CH2Cl2 (5 mL) was added slowly to the stirred heterogeneous mixture. A condenser was attached to the flask and the reaction was heated to reflux. Disappearance of 1A was monitored by thin-layer chromatography (EtOAc–hexane, 1:4; panisaldehyde/sulfuric acid as staining agent). Upon complete disappearance of 1A (ca. 2 h), the reaction mixture was filtered through a sintered glass funnel, the solid residue was washed with additional CH2Cl2 (3 × 10 mL), and the washings were added to the filtrate. Removal of solvent from the organic solution under vacuum gave an orange solid. Radial chromatography of the crude product (EtOAc–hexane, 1:9) gave 1, 4-benzoquinone 2A (89 mg, 82percent) as an orange solid.Alkylation of hydroquinone with tert-butanol was carried outin an autoclave equipped with a magnetic stirrer. Typically, 0.5 ghydroquinone, 1.0 g tert-butanol, and 0.20 g catalyst were addedto the autoclave, along with 2 g of xylene as a solvent. The reac-tion lasted 4 h under 150C. The products were analyzed witha gas chromatograph equipped with a SE-30 capillary column(30 m × 0.25 mm × 0.3 m) and a flame ionization detector. Thetemperature of the capillary column was set at 180C. The mainproducts were 2-tert-butyl hydroquinone (2-TBHQ), 2, 5-di-tert-butyl hydroquinone (2, 5-TBHQ), 2, 5-di-tert-butyl benzoquinone(2, 5-DTBBQ) and tert-butyl phenol ether (TBPE).A method as claimed in claim 22 wherein the quinone is selected from the group consisting of...2-methyl-p-benzoquinone2, 5-dimethyl-p-benzoquinone2, 6-dimethyl-p-benzoquinone2-t-Butyl-p-benzoquinone2, 5-di-t-butyl-p-benzoquinone2, 6-di-t-butyl-p-benzoquinone2-methyl-1, 4-napthaquinoneAn optically pumped laser as claimed in claim 29 wherein the quinone is selected from the group consisting of:...2, 5-dimethyl-p-benzoquinone2, 6-dimethyl-p-benzoquinone2, 3, 6-trimethyl-p-benzoquinone2-t-Butyl-p-benzoquinone2, 5-di-t-butyl-p-benzoquinone2. 6-di-t-butyl-p-benzoquinone2-methyl-1, 4-napthaquinone

Molecular Weight:220.31
XLogP3:3.4
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:2
Exact Mass:220.146329876
Monoisotopic Mass:220.146329876
Topological Polar Surface Area:34.1
Heavy Atom Count:16
Complexity:355
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes