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C. C. Pham et al.
PAPER
mg) and stirred for 12 h at which time TLC analysis (CHCl3) indi-
cated consumption of starting material. The reaction mixture was
concentrated to dryness and purified by column chromatography
(CHCl3–MeOH, 30:1) to give analytically pure 43;42 yield: 117.6
mg (54%); cream colored solid.
1H NMR (400 MHz, CDCl3 + 5% CD3OD): δ = 0.92–0.95 (2 d, J =
6.9 Hz, 12 H), 1.15 (t, J = 7.2 Hz, 6 H), 2.29 (sept, J = 6.9 Hz, 2 H),
4.09 (q, J = 7.2 Hz, 4 H), 5.45 (s, 1 H), 6.77 (s, 2 H), 6.94–6.96 (d,
J = 2.7 Hz, 2 H), 7.14–7.17 (m, 3 H).
1H NMR (400 MHz, CDCl3): δ = 0.87–0.91 (m, 12 H), 1.22 (t, J =
6.9 Hz, 6 H), 2.04–2.07 (m, 6 H), 4.09–4.18 (m, 4 H), 5.65 (s, 1 H),
6.90 (d, J = 2.7 Hz, 2 H), 7.09–7.11 (m, 2 H), 7.24–7.30 (m, 3 H),
9.86 (s, 2 H).
13C NMR (75 MHz, CDCl3): δ = 14.5, 22.5, 26.3, 39.8, 45.7, 60.6,
111.9, 119.7, 121.1, 127.8, 128.3, 128.6, 129.2, 137.5, 160.9, 172.4.
MS: m/z (M + H) calcd for C31H41N4O6: 565.68; found: 565 (95%);
m/z (M + Na) calcd for C31H41N4O6 + Na: 587.66; found: 587
(100%).
13C NMR (75 MHz, CDCl3 + 5% CD3OD): δ = 14.3, 19.3, 19.6,
35.2, 60.5, 112.4, 120.4, 127.7, 128.7, 129.0, 138.2, 161.3, 177.3.
Dipyrrole 50
Yield: 0.60 g (37%); yellow solid.
1H NMR (400 MHz, CDCl3): δ = 0.81 (t, J = 7.2 Hz, 3 H), 1.27 (t,
J = 7.2 Hz, 6 H), 2.01 (q, J = 7.6 Hz, 2 H), 4.22 (q, J = 6.4 Hz, 4 H),
4.32 (t, J = 8.0 Hz, 1 H), 6.82 (d, J = 2.4 Hz, 2 H), 7.38 (t, J = 7.2
Hz, 4 H), 7.50 (t, J = 7.2 Hz, 2 H), 7.85 (d, J = 7.2 Hz, 4 H), 8.33 (s,
2 H), 10.71 (s, 2 H). Traces of Et2O are present in the spectrum pro-
vided in the Supporting Information.
Dipyrrole 44
Yield: 57.0 mg (70%); white solid.
1H NMR (400 MHz, CDCl3): δ = 0.88 (t, J = 7.2 Hz, 3 H), 0.93 (t,
J = 7.2 Hz, 6 H), 1.35–1.39 (m, 4 H), 1.49–1.51 (m, 4 H), 2.17
(quint, J = 7.6 Hz, 2 H), 2.37–2.49 (m, 4 H), 3.78 (s, 6 H), 4.12 (t,
J = 7.6 Hz, 1 H), 6.75 (d, J = 2.8 Hz, 2 H), 10.32 (s, 2 H).
13C NMR (100 MHz, CDCl3): δ = 12.3, 13.6, 22.3, 25.2, 27.0, 32.9,
13C NMR (75 MHz, CDCl3): δ = 13.8, 14.5, 18.3, 20.9, 34.9, 60.5,
35.0, 51.4, 116.5, 120.6, 123.3, 135.6, 162.7.
112.4, 118.8, 120.8, 127.5, 128.7, 131.9, 132.0, 134.1, 161.3, 167.6.
MS: m/z calcd for C32H35N4O6: 571.64 (M + H); found: 571 (100%);
m/z (M + Na) calcd for C32H34N4O6 + Na: 593.63; found: 593
(40%).
Dipyrrole 45
Yield: 77 mg (70%); tan solid.
1H NMR (400 MHz, CDCl3): δ = 0.89 (t, J = 7.2 Hz, 3 H), 0.91 (d,
J = 6.8 Hz, 12 H), 1.39 (q, J = 8.0 Hz, 4 H), 1.59 (sept, J = 6.4 Hz,
2 H), 2.13 (quint, J = 7.0 Hz, 2 H), 2.33–2.47 (m, 4 H), 3.78 (s, 6
H), 4.10 (t, J = 8.0 Hz, 1 H), 6.74 (d, J = 2.4 Hz, 2 H), 10.00 (s, 2 H).
Dipyrrole 52
Yield: 6.6 mg (11%); beige powder.
1H NMR (400 MHz, CDCl3): δ = 0.83 (t, J = 6.4 Hz, 6 H), 1.25 (m),
1.33 (t, J = 7.2 Hz, 6 H), 2.58 (m, 4 H), 4.29 (q, J = 7.2 Hz, 4 H),
5.18 (s, 1 H), 6.29 (d, J = 2.8 Hz, 2 H), 7.15–7.18 (m, 3 H), 7.23–
7.27 (m, 2 H), 8.73 (s, 2 H).
Dipyrrole 46
Yield: 21.2 mg (32%); cream colored solid.
1H NMR (400 MHz, CDCl3): δ = 0.76 (t, J = 7.2 Hz, 3 H), 1.11 (sext,
J = 8.0 Hz, 2 H), 2.00 (q, J = 7.6 Hz, 2 H), 3.69 (br s, 4 H), 3.80 (s,
6 H), 4.20 (t, J = 8.0 Hz, 1 H), 6.68 (d, J = 2.4 Hz, 2 H), 7.07–7.09
(m, 4 H), 7.17–7.21 (m, 2 H), 7.24–7.28 (m, 4 H), 10.26 (s, 2 H).
13C NMR (100 MHz, CDCl3): δ = 13.9, 14.3, 25.1, 30.5, 32.1, 39.1,
60.0, 119.8, 121.8, 126.5, 128.6, 128.8, 128.9, 131.2, 144.8, 162.2.
Dipyrrole 53
Yield: 70.0 mg (63%); white powder.
13C NMR (100 MHz, CDCl3): δ = 13.4, 21.9, 24.8, 32.1, 39.9, 51.1,
116.6, 121.0, 124.0, 127.9, 129.4, 132.9, 161.9.
1H NMR (400 MHz, CDCl3): δ = 0.9 (t, J = 6.8 Hz, 6 H), 1.28–1.36
(m, ~12 H), 1.52 (quint, J = 7.6 Hz, 4 H), 1.79 (s, 6 H), 2.70 (q, J =
7.2 Hz, 4 H), 4.25 (q, J = 7.2 Hz, 4 H), 5.50 (s, 1 H), 7.11 (m, 2 H),
7.30–7.35 (m, 3 H), 8.28 (s, 2 H).
MS: m/z calcd for C30H33N2O4: 485.59 (M + H); found: 485 (85%);
m/z (M + Na) calcd for C30H32N2O4 + Na: 507.57; found: 507
(100%).
13C NMR (100 MHz, CDCl3): δ = 8.28, 13.7, 14.0, 22.2, 24.9, 30.2,
31.7, 41.0, 59.6, 117.6, 117.7, 127.8, 128.6, 129.4, 132.0, 133.3,
139.3, 162.1.
Dipyrrole 47
Yield: 70 mg (34%); pale yellow solid.
1H NMR (400 MHz, CDCl3): δ = 0.73 (t, J = 7.2 Hz, 3 H), 1.81
(quint, J = 7.6 Hz, 2 H), 2.62–2.67 (m, 4 H), 2.74–2.79 (m, 4 H),
3.77 (t, J = 8.0 Hz, 1 H), 3.80 (s, 6 H), 6.76 (d, J = 2.4 Hz, 2 H),
7.08–7.10 (m, 4 H), 7.18–7.24 (m, 6 H), 9.50 (s, 2 H).
Dipyrrole 54
Yield: 21.5 mg (18%); orange oil.
1H NMR (400 MHz, CDCl3): δ = 1.06 (t, J = 6.9 Hz, 6 H), 1.81 (s,
6 H), 4.06 (q, J = 7.2 Hz, 4 H), 5.64 (s, 1 H), 7.21–7.24 (m, 2 H),
7.30–7.41 (m, 13 H), 8.81 (s, 2 H).
MS: m/z (M + H) calcd for C31H35N2O4: 499.61; found: 499 (45%);
m/z (M + Na) calcd for C31H34N2O4 + Na 533.60; found: 521 (55%).
13C NMR (75 MHz, CDCl3): δ = 9.6, 14.1, 41.4, 60.1, 117.8, 117.9,
126.8, 127.5, 127.8, 128.5, 129.4, 130.5, 131.8, 132.4, 134.8, 138.8,
161.4.
Dipyrrole 48
Yield: 151.0 mg (64%); cream colored solid.
1H NMR (400 MHz, CDCl3): δ = 0.62 (d, J = 6.6 Hz, 6 H), 0.66 (d,
J = 6.6 Hz, 6 H), 1.29 (sept, J = 6.6 Hz, 2 H), 1.95 (d, J = 7.2 Hz, 4
H), 3.81 (s, 6 H), 3.88 (d, J = 7.8 Hz, 2 H), 4.71 (t, J = 7.8 Hz, 1 H),
6.67 (d, J = 2.7 Hz, 2 H), 6.99 (d, J = 7.2 Hz, 1 H), 7.20 (m, 1 H),
7.44–7.47 (m, 2 H), 7.66 (m, 1 H), 7.82–7.84 (m, 1 H), 7.99–8.01
(m, 1 H), 10.20 (s, 2 H).
13C NMR (75 MHz, CDCl3): δ = 22.8, 29.9, 35.2, 35.5, 38.1, 52.2,
117.7, 121.2, 122.9, 123.5, 125.8, 126.0, 126.5, 127.6, 127.8, 129.5,
132.1, 134.5, 135.2, 135.8, 163.1.
MS: m/z calcd for C35H35N2O4: 547.66 (M + H); found: 547 (100%);
m/z (M + Na) calcd for C35H34N2O4 + Na: 569.65; found: 569
(30%).
Saponification of Dipyrrole 44 to Diacid-Dipyrrole 55
Dipyrrole 44 (46.5 mg, 0.115 mmol) and LiOH (28 mg, 1.15 mmol)
were heated in 1:1 THF–H2O (2 mL) at 70 °C for 2 h.33 EtOH (4
mL) was added and TLC analysis clearly indicated consumption of
starting material. The reaction was further diluted with H2O (20
mL), acidified to pH ~3 with aq 1 M HCl and extracted with CHCl3
(3 × 15 mL). The combined CHCl3 layers were dried (Na2SO4), fil-
tered, and concentrated to give the title compound; yield: 42.0 mg
(~100%); red-brown crystals.
MS: m/z (M + H) calcd for C32H39N2O4: 515.66; found: 515 (70%);
m/z (M + Na) calcd for C32H38N2O4 + Na: 537.64; found: 537
(90%).
Dipyrrole 49
Yield: 14.6 mg (54%); white solid.
Synthesis 2013, 45, 1165–1173
© Georg Thieme Verlag Stuttgart · New York