ACCEPTED MANUSCRIPT
ArC), 125.9 (3,3‘-ArC), 126.9 (2,2‘-ArC), 139.4 (4,4‘-ArC), 161.9 (1,1‘-ArC). IR (ATR):
3582, 3258, 3052, 1588, 1472, 1431, 1335, 1305, 1207, 1125, 1088, 959, 916, 836, 786, 748,
720. m/z (ESI+) = 312.83 [M+Na]+, calc. 313.22.
6,6’-Methylenebis(2-bromo-4-nitrophenol) (2). To a solution of boric acid (42.80 mg,
692.2 µmol) in ethanol (35 ml), hydrogen peroxide (30 %, 4.74 ml, 46.40 mmol), 2,2’-
methylenebis(4-nitrophenol) (1) (2.00 g, 6.90 mmol), potassium bromide (1.81 g,
15.21 mmol) and sulfuric acid (5 , 2.00 ml) were added. The resulting mixture was stirred at
M
room temperature for 20 h and finally extracted with MTBE (3x). In order to destroy
excessive H2O2, the combined organic phases are washed with saturated Na2SO3 solution,
followed by water. The organic phase was dried over sodium sulfate, with the solvent being
subsequently removed to yield a pale yellow solid. Yield 92 % (2.84 g). M. p. 251-253 °C
(Sublimation). Rf = 0.49 [SiO2; n-hexane/ethyl acetate (8:2)]. 1H NMR (500 MHz, DMSO-d6)
δ = 4.13 (s, 2H, ArCH2Ar), 8.04 (d, 4J = 2.7 Hz, 2H, 5,5’-ArH), 8.28 (d, 4J = 2.6 Hz, 2H, 3,3’-
13
ArH). C NMR (125 MHz, DMSO-d6) δ = 31.8 (ArCH2Ar), 110.7 (2,2’-ArC), 125.1 (3,3’-
ArC), 127.0 (5,5’-ArC), 128.7 (6,6’-ArC), 139.1 (4,4’-ArC), 159.7 (1,1’-ArC). IR (ATR):
3245, 2998, 1574, 1526, 1459, 1355, 1345, 1150, 1090, 970, 978, 815, 760. m/z (ESI-) =
446.8 [M-H]-, calc. 447.0.
6,6’-Methylenebis(2-bromo-4-nitroanisole) (3). 6,6’-Methylene(2-bromo-4-nitrophenol) (2)
(1.00 g, 2.23 mmol), potassium carbonate (1.86 g, 13.46 mmol) and methyl iodide (3.08 ml,
49.26 mmol) were added to 10 ml acetone. The resulting pale yellow suspension was refluxed
for 7 h. After cooling to room temperature the precipitate was filtered and washed several
times with water. The crude product was purified by flash chromatography [SiO2; n-
hexane/ethyl acetate (8:2)]. Yield 96 % (1.02 g). M. p. 127-131 °C. Rf = 0.51 [SiO2; n-
1
hexane/ethyl acetate (8:2)]. H NMR (500 MHz, CDCl3) δ = 3.92 (s, 6H, CH3), 4.19 (s, 2H,
ArCH2Ar), 7.96 (d, 4J = 2.7 Hz, 2H, 5,5’-ArH), 8.38 (d, 4J = 2.8 Hz, 2H, 3,3’-ArH). 13C-NMR
(125 MHz, CDCl3) δ = 32.1 (ArCH2Ar), 61.7 (CH3), 118.2 (2,2’-ArC), 125.4 (3,3’-ArC),
128.7 (5,5’-ArC), 135.6 (6,6’-ArC), 144.5 (4,4’-ArC), 161.2 (1,1’-ArC). IR (ATR): 2952,
1615, 1545, 1515, 1500, 1475, 1398, 1245, 1090, 1029, 946, 880, 865, 790. m/z 476 [M]+,
calc. 476.
Bis(6-nitro-4H-benzo[d][1,3]dioxin-8-yl)methane (4). 2,2’-Methylenebis(4-nitrophenol) (1)
(5.00 g, 17.23 mmol) was added to an aqueous solution of formaldehyde (37 wt %, 5.36 ml,
71.98 mmol) and heated to 90 °C. A mixture of 15.0 ml concentrated sulphuric acid and 4.0
ml of water was added dropwise to the hot solution. The resulting pale yellow suspension was
heated for an additional hour. After cooling to room temperature the precipitate formed was
filtered off und washed with a diluted sodium hydroxide solution to obtain a pale yellow
solid. Yield 70 % (4.51 g). M. p. 222-224 °C (lit.:18 225 °C). Rf = 0.55 [SiO2; n-hexane/ethyl
1
acetate (7:3)]. H NMR (500 MHz, DMSO-d6) δ = 3.99 (s, 2H, ArCH2Ar), 5.01 (s, 4H,
13
ArCH2O), 5.42 (s, 4H, OCH2O), 7.87 (s, 2H, 7,7’-ArH), 8.01 (s, 2H, 5,5’-ArH). C-NMR
(125 MHz, CDCl3) δ = 27.9 (ArCH2Ar), 65.4 (ArCH2O), 91.8 (OCH2O), 120.5 (5,5’-ArC),
122.2 (4a,4a’-ArC), 123.6 (7,7’-ArC), 127.6 (8,8’-ArC), 140.4 (6,6’-ArC), 155.7 (8a,8a’-
ArC). IR (KBr): 3076, 2869, 1617, 1593, 1514, 1465, 1339, 1269, 1239, 1155, 1083, 1003,
952, 907, 809, 779, 747, 732, 702. m/z (ESI-) [M-H]- 373.7, calc. 373.3.
2,2’-Methylenebis(4-nitroanisole) (5). Bisphenol 1 (4.00 g, 13.78 mmol), potassium
carbonate (20.40 g, 147.6 mmol) and methyl iodide (9.0 ml, 144.9 mmol) were added to a
solution of 800 ml acetonitrile and 200 ml dimethylformamide. The resulting pale yellow
suspension was refluxed for 5 h and then acetonitrile was removed under vacuum.
Afterwards, hydrochloric acid (1
M
, 500 ml) was added to the residue, then the precipitate
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