News:

Registration doesn't require a real email.
Monero Donation Address: 897ESh4QoJgEytJueBPULziMDfNMToXkGMrvtUCJRo2NQRv2CXACHnmEzeMTkwQhnfcZsAc3ctXp6GsedhMfBv983rn5i84

Main Menu

Big Breakthrough for Benzo Bees

Started by Bond_DoubleBond, November 26, 2003, 06:22:00 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Print
Go Down Pages 1 2 All
User actions

Rhodium

#20
July 06, 2004, 06:25:00 AM
Facile and convenient syntheses of quinones from phenols
F. Minisci, A. Citterio, E. Vismara, F. Fontana, S. DeBernardinis, M. Correale

J. Org. Chem. 54, 728-731 (1989)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/hydroquinone2benzoquinone.h2o2-i2.pdf)


General Procedures for the Oxidation of Hydroquinone to Benzoquinone

(A) H2O2 (60%) (10.0 mL, 0.22 mol) was added dropwise with stirring to a solution of Hydroquinone (0.20 mol), I2 (0.01 mol), and concentrated H2SO4 (10 mL) in methanol (600 mL) at room temperature. After 4 h part of the formed quinone crystallized and was collected by filtration. The methanolic solution was poured in 100 mL of water and extracted with ether, and the solvent evaporated to give crude benzoquinone. Yield 97%.

(B) A procedure similar to A, with the only difference that water was used instead of methanol. In this way the benzoquinone directly crystallized from the aqueous solution and was easily separated by simple filtration. Yield 93%.

(C) A procedure similar to A was followed with the difference that 20 mmol of HI was utilized instead of I2. Yield 95%.

(D) A procedure similar to B was followed with the difference that 20 mmol of HI was utilized instead of I2. Yield 93%.

(E) The same procedure as in A was used, with the difference that 10 mmol of Br2 was utilized instead of I2. Yield 52%.

Print
Go Up Pages 1 2 All
User actions