Окисненням 2-арил-6,7-диметил-1,4-нафтохінонів 1–6 (арил = C6H5 (1), 4-MeC6H4 (2),
4-EtOC6H4 (3), 4-FC6H4 (4), 3-ClC6H4 (5), 2,5-Cl2C6H3 (6)) пероксидом водню одержано 2-арил-2,3-дигідро-2,3-епокси-6,7-диметил-1,4-нафтохінони 7–12. Виявлено умови
розкриття епоксидного циклу дією N-нуклеофільних реагентів, внаслідок чого Туворюються з добрими виходами відповідні амінопохідні 1,4-нафтохінону 13–18. Досліджено реакції епокси-1,4-нафтохінонів з деякими амбідентними нуклеофілами.
Ключові слова: 2-арил-1,4-бензохінони, арилнафтохінони, епокси-1,4-нафтохінони,
похідні нафтохінону, амбідентні нуклеофіли.
The paper are devoted to the synthesis of epoxyarylnaphthoquinones and the studying of the oxirane ring
disclosing of its.
2-Aryl-2,3-dihydro-2,3-epoxy-6,7-dimethyl-1,4-naphthoquinones 7–12 were synthesized in a high yield by
the oxidation reaction of 2-aryl-6,7-dimethyl-1,4-naphthoquinones 1–6 with hydrogen peroxide in the presence
of potassium carbonate. Such as the epoxidation reaction of the α,β-unsaturated ketones, reaction of quinones
are occurred as a nucleophilic hydroperoxide anion addition to the C=C bond of the quinone ring with
following intramolecular cyclization. Obtained epoxy-1,4-naphthoquinones were studied in the reactions of Nand
S-nucleophiles.
The substituted 2-R1R
2
-amino-3-aryl-6,7-dimethyl-1,4-naphthoquinones 13–18 were obtained via the
reaction of amines with 2,3-epoxy-1,4-naphthoquinones 7, 12. Reaction mechanism include the formation of
intermediate adduct with following water elimination. In the oxirane ring opening reactions with secondary
aliphatic amines, particularly morpholine (compounds 17, 18) the yields of the aminonaphthoquinones were
high.
The reaction of 2,3-epoxy-1,4-naphthoquinones with potassium thiocyanate and thiourea was investigated
for conversion of the oxirane to the thiirane ring. It was found that the reaction of the epoxyquinones with
potassium thiocyanate leads to the C–O bond breaking and the formation of the bis-(3-aryl-6,7-dimethyl-1,4-
naphthoquinone)-2,2'-sulfides 19–21 without closing the oxirane rings. Compounds with thiirane rings were
not obtained. These reactions were carried out under heating of the equimolar amounts of the corresponding
epoxynaphthoquinones with potassium thiocyanate in water alcohol.
6,7-Dimethyl-3-(4-methylphenyl)-1,4-dioxo-1,4-dihydronaphthalen-2-yl imidothiocarbamate 22 was formed
by the reaction of the 2,3-epoxy-2,3-dihydro-6,7-dimethyl-2-(4-methylphenyl)-1,4-naphthoquinone 8 with
thiourea at the room temperature in ethanol medium.
The mechanisms of the epoxidation reaction of the quinones and the reaction sulfides formation 19–21
were discussed.
2-Aryl-6,7-dimethyl-1,4-naphthoquinones 1–6 were obtained via the diene synthesis by the reaction of 2-
aryl-1,4-benzoquinones with 2,3-dimethyl-1,3-butadiene.
The structures of the compounds 7–22 were confirmed by the 1H NMR spectroscopy and element analysis
data.
As a result of our studies we suggested a convenient way of epoxy-1,4-naphthoquinones synthesis, showed
the considerable synthetic possibilities of the epoxycompounds, which easily opened epoxy ring under the
action of nucleophilic reagents and may be used in molecular design of the naphthoquinones.
Key words: 2-aryl-1,4-benzoquinones, arylnaphthoquinones, epoxy-1,4-naphthoquinones, naphthoquinone
derivatives, ambident nucleophiles.
Окислением 2-арил-6,7-диметил-1,4-нафтохинонов 1–6 (арил = C6H5 (1), 4-MeC6H4 (2), 4-EtOC6H4
(3), 4-FC6H4 (4), 3-ClC6H4 (5), 2,5-Cl2C6H3 (6)) пероксидом водорода получили 2-арил-2,3-дигидро-6,7-
диметил-2,3-эпокси-1,4-нафтохиноны 7–12. Определены условия раскрытия эпоксидного цикла деїствием N-нуклеофильных реагентов, вследствие чего с хорошими выходами получены соответствующие
аминопроизводные 1,4-нафтохинона 13–18. Исследованы реакции эпокси-1,4-нафтохинонов с некоторыми амбидентными нуклеофилами.
Ключевые слова: 2-арил-1,4-бензохиноны, арилнафтохиноны, эпокси-1,4-нафтохиноны, производные нафтохинона, амбидентные нуклеофилы.
