Author Topic: 1,4-naphthoquinone from naphthalene  (Read 1113 times)

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pHarmacist

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1,4-naphthoquinone from naphthalene
« on: July 21, 2003, 04:34:00 AM »
I'm posting this synth as the product of it serves as a staring material in the synthesis of the long-lived 2C-G-N. Also, those that are unlike me interested in MDxA synthesis can try this out and see how effective 1,4-naphthoquinone is as an oxygen donator in contrast to p-benzoquinone in Wacker process, involving donation of oxygen to the pi-bond of safrol. Advantage, as I see it, is that 1,4-naphthoquinone can bee prepared via direct oxidation of common, non-suspicious, cheap naphthalene. Make it harder for DEA.

Place a solution of 120 g (1.2 mol) of pure chromium trioxide in 150 mL of 80 per cent aqueous acetic acid in a 2-litre three-necked flask, fitted with a thermometer, mechanical stirrer and 1-litre dropping funnel. Surround the flask by a mixture of ice and salt and, when the temperature has fallen to 0 Celsius, add a solution of 64 g (0.5 mol) of pure naphtalene in 600 mL of glacial acetic acid, with constant stirring, over a period of 2-3 hours while maintaining the internal temperature at 10-15°C. Continue the stirring overnight, during which time the reaction mixture and bath attain room T. Allow the dark green solution to stand for 3 days and stirr occasionally. Pour the reaction mixture into 5-6 litres of water, collect the crude naphtoquinone by suction filtration, wash with 200 mL of water and dry in a desiccator. Recrystallise from 500 mL of petroleum ether (b.p. 80-100°C). The yield of pure 1,4-naphtoquinone, m.p. 124-125°C, is 17 g (22%)  :(


hest

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NAphtoquinon
« Reply #1 on: July 21, 2003, 04:49:00 AM »
Juaristi, M.; Aizpurua, J. M.; Lecea, B.; Palomo, C.; CJCHAG; Can.J.Chem.; EN; 62; 1984; 2941-2944
These gues use chromiumtrioxide in acetic at 50-60°C for 120min and some 18-crown-6 ether. yeald 50%

pHarmacist

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Ok, häst
« Reply #2 on: July 21, 2003, 04:51:00 AM »
Fotgot to mention that I found the synth in Vogel's 5:th p 1022...  8)


pHarmacist

  • Guest
hmm...
« Reply #3 on: July 28, 2003, 08:12:00 AM »
I could not help but to observe that my karma score increased by 0.5 after the above post (the first one), but I see no rating so that it can be found among good ones using our beloved but yet so fucking search engine...

EDIT: These gues

LOOL hest!