Mono carbonylation of benzene diols
Patent: US2004260114
A process for a mono carbonylation of a benzenediol of the formula (I) is characterized in that a benzene diol of the formula (II) is reacted with an
acid anhydride or carbonyl halide of the formula (III) without any organic or inorganic bases for thereby producing a monocarbonylated benzenediol of
the formula (I): wherein R is hydrogen, C1-C15 alkyl group, cycle alkyl group, aryl group, alkoxy group, aryloxy group, dialkylamino group,
alkylarylamino group or diarylamino group, and X is a general leaving group such as fluoride, chloride, bromide, iodide, acetoxy, etc.
EX:
Preparation of monoacetyl hydroquinone
In the solution of 220 g(2 mol) of hydroquinone in 500 ml of acetic acid, 102 g(1 mol) of acetic anhydride was drop-added for one hour while agitating
the solution at 110[deg.] C. The mixture was maintained at 110[deg.] C. for two hours, and acetic acid was distilled under vacuum. 1 liter of toluene
was added to the reaction mixture and the unreacted excess hydroquinone was filtered and collected (recovered amount: 110 g, recycled without any
purification process). A desired monoacetyl hydroquinone was obtained by evaporating the residue under vacuum. (Yield: 149.1 g(98%). mp: 60-62[deg.]
C., <1> H-NMR(200 MHz, CDCl3, ppm) 2.25(s, 3H), 5.78 (br, 1H), 6.70 (d,2H), 6.88 (d, 2H).
Preparation of mono acetyl resorcinol
In the solution of 220 g(2 mol) of resorcinol in 500 ml of acetic acid, 102 g(1 mol) of acetic anhydride was drop-added for one hour while agitating
the solution at 110[deg.] C. The mixture was maintained at 110[deg.] C. for two hours, and acetic acid was distilled under vacuum. 1 liter of toluene
was added to the reaction mixture and the unreacted excess hydroquinone was filtered and collected (recovered amount: 110 g, recycled without any
purification process). A desired mono acetyl resorcinol was obtained by evaporating the residue under vacuum. (Yield: 149.7 g(98%). mp:
oil, <1> H-NMR(200 MHz, CDCl3, ppm) 2.29(s, 3H), 6.53-6.67 (m, 4H), 7.18 (t. 1H).
Preparation of mono acetyl catechol
In the solution of 220 g(2 mol) of catechol in 500 ml of acetic acid, 102 g(1 mol) of acetic anhydride was drop-added for one hour while agitating the
solution at 110[deg.] C. The mixture was maintained at 110[deg.] C. for two hours, and diethylene glycol dibutyl ether was distilled under vacuum. 1
Liter of toluene was added to the reaction mixture and cooled to 0[deg.] C. and then the unreacted excess hydroquinone was filtered and collected
(recovered amount: 110 g, recycled without any purification process). A desired mono acetyl catechol was obtained by evaporating the residue in
vacuum. (Yield: 149.0 g(98%). mp: oil. <1> H-NMR(200 MHz, CDCl3, ppm) 2.33(s, 3H), 5.81 (br, 1H), 6.83-7.18 (m, 4H).
[Edited on 14-1-2005 by Sandmeyer]
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