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PAPER
neutralized with sat. aq Na2S2O3 (500 mL). The organic layer was
neutralized with 10% aq Na2CO3 and separated. The organic layer
was washed with sat. aq NaCl (2 × 300 mL), dried (Na2SO4), and
concentrated to dryness. The solid was recrystallized (EtOH); this
gave 8.
(d, J = 13.4 Hz, 1 H), 6.65 (s, 1 H), 5.93 (d, J = 12.7 Hz, 1 H), 5.88
(s, 2 H), 3.75 (t, J = 6.6 Hz, 2 H), 3.65 (s, 3 H), 2.80 (t, J = 6.8 Hz,
2 H), 1.93 (br, 1 H).
13C NMR (75MHz, CDCl3): δ (Z) = 146.9, 145.7, 145.4, 128.7,
127.5, 109.8, 109.3, 101.9, 100.6, 62.8, 60.3, 36.5; δ (E) = 148.9,
146.3, 145.9, 128.4, 128.3, 110.1, 105.6, 102.7, 100.7, 62.8, 56.6,
36.3.
Yield: 31.40 g (68%); colorless crystals.
1H NMR (300 MHz, CDCl3): δ = 10.17 (s, 1 H), 7.36 (s, 1 H), 7.26
(s, 1 H), 6.08 (s, 2 H).
MS (EI): (Z)-11: m/z (%) = 222 (88.13) [M+], 161 (100); (E)-11: m/z
(%) = 222 (100) [M+].
(Methoxymethyl)triphenylphosphonium Chloride (9)
A soln of Ph3P (10.00 g, 38.10 mmol) in CH2Cl2 (20 mL) was treat-
ed with MOMCl (3.20 mL, 42.60 mmol) and the mixture was stirred
overnight under reflux until no Ph3P was detected by TLC. The soln
changed to a suspension after cooling to r.t., and benzene (10 mL)
was added. CH2Cl2 and MOMCl were removed by vacuum distilla-
tion. Product 9 was collected by filtration and washed with petrol
ether.
HRMS (EI) (Z)-11: calcd for C12H14O4Na: 245.0784; found:
245.0788; (E)-11: calcd for C12H14O4Na: 245.0784; found:
245.0782.
2-{6-(2-Methoxyvinyl)benzo[d][1,3]dioxol-5-yl}ethyl 4-Methyl-
benzenesulfonate (12)
A soln of 11 (27 mg, 0.12 mmol) in CH2Cl2 (1 mL) was treated with
Et3N (0.1 mL) and TsCl (30 mg, 0.16 mmol) and the mixture was
stirred overnight at r.t. The soln was quenched with H2O (1 mL), the
organic soln was separated, and the aqueous layer was extracted by
CH2Cl2 (3 × 3 mL). The combined organic layer was concentrated
to dryness and the residue was purified by flash chromatography
(silica gel, PE–EtOAc, 6:1); this gave products (Z)-12 and (E)-12.
Yield: 14.50 g (100%); white solid.
1H NMR (300 MHz, CDCl3): δ = 7.87–7.61 (m, 15 H), 5.89 (d,
J = 4.0 Hz, 2 H), 3.69 (s, 3 H).
5-Bromo-6-(2-methoxyvinyl)benzo[d][1,3]dioxole (10)
A suspension of 9 (1.84 g, 5.38 mmol) in THF (20 mL) was treated
with t-BuOK (0.57 g, 5.38 mmol) and the mixture was stirred for 20
min at r.t. under an argon atmosphere. The color of the suspension
changed from white to brown. Then 8 (0.69 g, 3.00 mmol) was add-
ed and the mixture was stirred for 1.5 h at r.t. until no 8 was detect-
ed. The soln was quenched with sat. aq NH4Cl soln (40 mL), the
organic soln was separated, and the aqueous layer was extracted
with EtOAc (3 × 30 mL). The combined organic layer was dried
(Na2SO4), and concentrated to dryness; the residue was purified by
flash chromatography (silica gel, PE–EtOAc, 100:1); this gave the
products (Z)-10 and (E)-10.
(Z)-12: yield: 22 mg (47%); light yellow liquid.
(E)-12: yield: 23 mg (48%); light yellow liquid.
IR (KBr): (Z)-12: 2900, 1486, 1358, 1176, 1098 cm–1; (E)-12: 2900,
1639, 1487, 1357, 1176 cm–1.
1H NMR (300 MHz, CDCl3): δ (Z) = 7.71 (d, J = 8.2 Hz, 2 H), 7.37
(s, 1 H), 7.29 (d, J = 8.2 Hz, 2 H), 6.51 (s, 1 H), 6.07 (d, J = 7.2 Hz,
1 H), 5.90 (s, 2 H), 5.12 (d, J = 7.2 Hz, 1 H), 4.10 (t, J = 7.6 Hz, 2
H), 3.73 (s, 3 H), 2.91 (t, J = 7.6 Hz, 2 H), 2.44 (s, 3 H); δ (E) = 7.66
(d, J = 8.3 Hz, 2 H), 7.26 (d, J = 7.9 Hz, 2 H), 6.65 (s, 1 H), 6.64(d,
J = 12.6 Hz, 1 H) 6.49 (s, 1 H), 5.85 (s, 1 H), 5.75 (d, J = 12.7 Hz,
1 H), 4.07 (t, J = 7.4 Hz, 1 H).
(Z)-10: yield: 330 mg (43%); light yellow liquid.
(E)-10: yield: 330 mg (42%); light gray solid.
13C NMR (75MHz, CDCl3): δ (Z) = 147.3, 146.1, 145.4, 144.4,
132.6, 129.5, 127.6, 127.5, 125.9, 109.7, 109.3, 101.2, 100.6, 69.8,
60.3, 32.9, 21.4; δ (E) = 149.3, 146.7, 145.8, 144.5, 132.7, 129.5,
128.5, 127.5, 125.6, 109.9, 105.6, 101.7, 100.7, 69.5, 56.4, 32.8,
21.4.
IR (KBr): (Z)-10: 2937, 1648, 1477, 1090, 1040 cm–1; (E)-10: 3001,
1639, 1481, 1135, 1038 cm–1.
1H NMR (300 MHz, CDCl3): δ (Z) = 7.63 (s, 1 H), 7.00 (s, 1 H), 6.13
(d, J = 7.2 Hz, 1 H), 5.92 (s, 2 H), 5.52 (d, J = 7.2 Hz, 1 H), 3.73 (s,
3 H); δ (E) = 6.98 (s, 1 H), 6.85 (d, J = 12.9 Hz, 1 H), 6.80 (s, 1 H),
6.01 (d, J = 12.9 Hz, 1 H), 5.93 (s, 2 H), 3.70 (s, 3 H).
MS (EI): (Z)-12: m/z (%) = 376 (51.34) [M+], 161 (100); (E)-12: m/z
(%) = 376 (4.29) [M+], 161 (100).
HRMS (MALDI): m/z calcd for C19H21O6S: 377.1069; found:
377.1053.
13C NMR (75MHz, CDCl3): δ (Z) = 148.0, 146.9, 146.1, 128.5,
113.3, 112.3, 109.6, 103.8, 101.5, 60.7; δ (E) = 149.4, 147.4, 146.4,
129.4, 113.1, 112.5, 105.1, 104.4, 101.5, 56.4.
N-(2-{6-(2-Methoxyvinyl)benzo[d][1,3]dioxol-5-yl}ethyl)pent-
4-yn-1-amine (7)
MS (EI): m/z (%) = 256 (100) [M+].
A soln of 12 (142 mg, 0.32 mmol), TBAI (117 mg, 0.32 mmol), and
DIPEA (0.13 mL, 0.74 mmol) in THF (1.5 mL) was treated drop-
wise with pent-4-yn-1-amine (80 mg, 0.21 mmol) in THF (0.5 mL)
and the mixture was stirred for 3 h under reflux. The soln was con-
centrated to dryness and the residue was purified by flash chroma-
tography (silica gel, EtOAc–MeOH, 50:1); this gave 7.
HRMS (EI): m/z calcd for C10H9O3Br: 255.9730; found: 255.9747.
2-{6-(2-Methoxyvinyl)benzo[d][1,3]dioxol-5-yl}ethanol (11)
A soln of 10 (514 mg, 2.00 mmol) in THF (10 mL) was treated with
1.5 M t-BuLi in pentane (3.6 mL, 4.00 mmol) and the mixture was
stirred for 1 h at –78 °C under argon atmosphere. The color of the
soln changed from colorless to orange. Oxirane (0.35 ml, 6.00
mmol) was added and the mixture was stirred for 2 h at –78 °C and
16 h at r.t. The soln was quenched with sat. aq NH4Cl soln (1 mL)
and filtered. The organic soln was concentrated to dryness, and the
residue was purified by flash chromatography (silica gel, PE–
EtOAc, 4:1); this gave the products (Z)-11 and (E)-11.
Yield: 45 mg (74%); red solid.
1H NMR (300 MHz, CDCl3): δ = 6.75 (s, 1 H), 6.74 (d, J = 12.8 Hz,
1 H), 6.64 (s, 1 H), 5.94 (d, J = 12.8 Hz, 1 H), 5.88 (s, 2 H), 3.66 (s,
3 H), 2.83–2.67 (m, 6 H), 2.23 (dt, J = 2.7, 7.1 Hz, 2 H), 1.94 (t,
J = 2.7 Hz, 1 H), 1.68 (5, J = 7.1 Hz, 2 H), 1.43 (br, 1 H).
ESI-MS: m/z = 288.1 [M + H]+.
(Z)-11: yield: 156 mg (35%); light yellow liquid.
HRMS (EI): m/z calcd for C17H22O3N: 288.1585; found: 288.1594.
(E)-11: yield: 156 mg (35%); light yellow liquid.
IR (KBr): (Z)-11: 3369, 2939, 2884, 1648, 1484, 1099, 1041 cm–1;
(E)-11: 3387, 2939, 2886, 1639, 1504, 1485 cm–1.
1H NMR (300 MHz, CDCl3): δ (Z) = 7.48 (s, 1 H), 6.67 (s, 1 H), 6.11
(d, J = 7.1 Hz, 1 H), 5.92 (s, 2 H), 5.32 (d, J = 7.1 Hz, 1 H), 3.84–
3.66 (m, 5 H), 2.85 (t, J = 6.7 Hz, 2 H); δ (E) = 6.75 (s, 1 H), 6.73
tert-Butyl (2-{6-(2-Methoxyvinyl)benzo[d][1,3]dioxol-5-yl}eth-
yl)(pent-4-yn-1-yl)carbamate (13)
An emulsion of 7 (29 mg, 0.10 mmol) in CH2Cl2 (1 mL) and H2O
(1 mL) was treated with NaOH (4.40 mg, 0.11 mmol) and Boc2O
(24 mg, 0.11 mmol) in CH2Cl2 (1.00 mL) and the mixture was
stirred for 2 h at r.t. The emulsion was separated and the aqueous
Synthesis 2013, 45, 596–600
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