2124
M. Isobe et al. / Tetrahedron 58 -2002) 2117±2126
12c was synthesized according to the same procedures
described in 12a. 12c '184 mg) in 65% yield from 10c
'300 mg, 1.80 mmol) and 11 '200 mg, 0.72 mmol). Com-
pound 12c: UV 'MeOH/H2O1/2) lmax 'log 1), 433 '0.66),
'1H, t, J7.1Hz), 7.35±7.31 '3H, m), 7.41 '1H, t, J
7.8 Hz), 7.43 '1H, s), 7.48 '2H, d, J7.8 Hz), 7.55 '1H,
brd, J6.4 Hz), 7.74 '2H, d, J8.3 Hz), 7.90 '1H, s), 8.94
'1H, t, J7.6 Hz), 9.63 '1H, s) ppm. 13C NMR 'CD3OD,
125 MHz), d 109.3, 115.4, 120.3, 122.0, 125.2, 125.7,
1
259 '1.79) nm. H NMR 'CD3OD, 500 MHz), d 4.20 '2H,
s), 4.36 '2H, s), 6.83 '2H, d, J8.8 Hz), 7.07±7.04 '2H, m),
7.21±7.19 '5H, m), 7.36 '2H, d, J7.3 Hz), 7.44 '2H, d,
J8.8 Hz), 7.56 '1H, brs) ppm. 13C NMR 'CD3OD,
125 MHz), d 34.9, 40.6, 107.9, 116.1 'd, JC±F21.9 Hz),
116.9.0, 125.2, 126.7 'd, JC±F17.4 Hz), 128.2, 129.4,
129.7, 129.8, 132.1 'd, JC±F4.6 Hz), 138.0, 160.2, 162.3
'd, JC±F244 Hz) ppm. FAB-MS 'NBA) m/z 426 'MH1).
HRMS 'FAB/NBA) calcd for C26H21O2N3F 426.1618,
found 426.1638 'MH1).
125.8,126.5, 126.6,128.3, 129.5, 133.0, 133.7 'd, JC±F
9.0 Hz), 134.0, 136.5, 139.8, 149.0 'd, JC±F4.5 Hz),
157.3 'd, JC±F112 Hz), 166.5 ppm. 19F NMR 'DMSO-d6,
376 MHz), d 236.4 ppm. FAB-MS 'NBA) m/z 424 'MH1).
HRMS 'FAB/NBA) calcd for C26H19O2N3F 424.1461,
found 426.1459 'MH1). Anal. calcd for C26H19O2N3FF; C,
73.75; H, 4.28; N, 9.92%. Found C, 73.76; H, 4.33; N,
9.84%.
4.1.13. p-F-DTT adduct 316a). Dithiothreitol '14) '2.2 mg,
0.014 mmol) was added to a solution of dehydrocoelen-
terazine 13a '6.0 mg, 0.014 mmol) in MeOH '1.0 ml) and
CH2Cl2 '1.0 ml) at room temperature under argon atmos-
phere. After stirring for 2 h at room temperature, the reac-
tion mixture was concentrated under reduced pressure to
give a DTT adduct 16a '8.2 mg) as yellow oil compound
in quantitative yield. Compound 16a: UV 'MeOH/H2O1/
2) lmax 'log 1), 445 '1.46), 259 '1.20) nm. 1H NMR
'CD3OD, 600 MHz), d 2.55±2.50 '1H, m), 2.69±2.65
'1H, m), 3.57±3.53 '2H, m), 3.74±3.70 '2H, m), 4.45
'2H, AB), 5.56 '1H, s), 6.88 '2H, d, J8.3 Hz), 7.04 '2H,
t, J8.3 Hz), 7.24±7.22 '1H, m), 7.29 '2H, t, J7.4 Hz),
7.43 '2H, d, J8.8 Hz), 7.44 '2H, d, J7.3 Hz), 7.55 '1H,
s), 7.72 '2H, d, J11.7, 2.0 Hz) ppm. 19F NMR 'DMSO-d6,
376 MHz), d 250.68 ppm. FAB-MS 'NBA) m/z 578
'MH1). HRMS 'FAB/NBA) calcd for C30H29O4N3FS2
578.1584, found 578.1581 'MH1).
4.1.10. 4-Fluorodehydrocoelenterazine 313a). Manganese
'II) oxide '1.2 g, 1.3 mmol) was added to the solution of
4-¯uorocoelenterazine 12a '123 mg, 0.29 mmol) in ether
'150 ml) and ethanol '30 ml) at 08C. The mixture was stirred
at 08C for 2 h. The solution was ®ltered through a pad of
Celite and then concentrated under reduced pressure to dry.
The residue was chromatographed on silica gel with 5%
MeOH/CH2Cl2 to give 90 mg of 13a as dark purple
amorphous powder in 74% yield. Compound 13a: UV
'MeOH/H2O1/2) lmax 'log 1), 537 '0.28), 346 '1.14),
1
278 '1.75) nm. H NMR 'DMSO-d6, 500 MHz), d 4.28
'2H, s), 7.23 '1H, m), 7.33 '2H, t, J7.6 Hz), 7.37 '2H, t,
J8.8 Hz), 7.47 '2H, d, J9.8 Hz), 7.48 '1H, s), 7.73 '2H,
d, J8.8 Hz), 7.87 '1H, s), 8.43 '2H, m), 9.73 '1H, s) ppm.
13C NMR 'DMSO-d6, 125 MHz), d 109.4, 115.7, 116.4 'd,
JC±F20.0 Hz), 126.1, 126.8, 128.5, 129.6, 130.9, 133.9,
135.9 'd, JC±F4.5 Hz), 136.7, 148.3, 157.5 'd, JC±F
80.3 Hz), 166.7 ppm. FAB-MS 'NBA) m/z 424 'MH1).
19F NMR 'DMSO-d6, 376 MHz), d 239.33 ppm. HRMS
'FAB/NBA) calcd for C26H19O2N3F 424.1461, found
424.1454 'MH1).
4.1.14. m-F-DTT adduct 316b). 16b '8.2 mg) was synthe-
sized from 13b '6.0 mg, 0.014 mmol) and 14 '2.2 mg,
0.014 mmol) in quantitative yield according to the same
procedures described in 16a. Compound 13b: UV
'MeOH/H2O1/2) lmax 'log 1), 438 '0.55), 261'.160)
4.1.11. 3-Fluorodehydrocoelenterazine 313b). 13b was
synthesized according to the same procedures described in
13a. 13b '54 mg) in 77% yield from 12b '70 mg,
0.23 mmol) and manganese'II) oxide '1.23 g, 1.3 mmol).
Compound 13b: UV 'MeOH/H2O1/2) lmax 'log 1), 537
1
nm. H NMR 'CD3OD, 500 MHz), d 2.50±2.55 '1H, m),
2.68±2.72 '1H, m), 3.52±3.56 '2H, m), 3.60±3.65 '2H, m),
4.45 '2H, AB), 5.58 '1H, s), 6.87 '2H, d, J8.0 Hz), 6.96
'1H, t, J8.0 Hz), 7.16±7.33 '5H, m), 7.37±7.58 '5H, m)
ppm. 13C NMR 'CD3OD, 125 MHz), d 36.4, 36.6, 46.2,
58.3, 71.2, 75.3, 108.7, 108.8, 115.1 'd, JC±F21.9 Hz),
115.2 'd, JC±F21.0 Hz), 116.8, 117.0, 126.0, 128.3,
129.6, 129.8, 130.0, 130.9 'd, JC±F8.3 Hz), 137.9, 143.9
'd, JC±F6.4 Hz), 160.3, 164.2 'd, JC±F243 Hz) ppm. 19F
NMR 'DMSO-d6, 376 MHz), d 248.50 ppm. FAB-MS
'NBA) m/z 578 'MH1). HRMS 'FAB/NBA) calcd for
C30H29O4N3FS2 578.1584, found 578.1559 'MH1).
1
'0.12), 351 '0.66), 271 '1.19) nm. H NMR 'DMSO-d6,
500 MHz), d 4.29 '2H, s), 6.81'2H, d, J8.8 Hz), 7.23
'1H, t, J7.6 Hz), 7.33 '2H, t, J7.6 Hz), 7.33 '1H, t, J
7.6 Hz), 7.48 '2H, d, J6.8 Hz), 7.48 '1H, s), 7.55 '1H, m),
7.76 '2H, d, J8.3 Hz), 7.94 '1H, s), 8.09 '1H, d, J
7.8 Hz), 8.31'1H, d, J11.0 Hz), 9.65 '1H, s) ppm. 13C
NMR 'CD3OD, 125 MHz), d 109.3, 115.5, 118.0 'd,
JC±F20.0 Hz), 118.5 'd, JC±F20.0 Hz), 125.8, 126.6,
126.6,128.3, 129.5, 129.7, 130.8, 133.9, 136.5, 139.7,
148.8, 157.3 'd, JC±F105 Hz), 166.5 ppm. 19F NMR
'DMSO-d6, 376 MHz), d 239.01ppm. FAB-MS 'NBA)
m/z 424 'MH1). HRMS 'FAB/NBA) calcd for
C26H19O2N3F 424.1461, found 426.11452 'MH1).
4.1.15. o-F-DTT adduct 316c). 16c '8.2 mg) was synthe-
sized from 13c '6.0 mg, 0.014 mmol) and 14 '2.2 mg,
0.014 mmol) in quantitative yield according to the same
procedures described in 16a. Compound 13c: UV 'MeOH/
H2O1/2) lmax 'log 1), 440 '0.90), 260 '2.45) nm. 1H NMR
'CD3OD, 500 MHz), d 4.43 '2H, AB), 4.53 '1H, brs), 5.90
'1H, AB), 6.88 '2H, d, J8.8 Hz), 7.02 '1H, d, J8.8 Hz),
7.07 '1H, td, J8.5, 1.5 Hz), 7.15±7.30 '5H, m), 7.43 '2H,
d, J8.8 Hz), 7.54 '1H, d, J6.4 Hz), 8.04 '1H, td, J7.8,
1.5 Hz) ppm. 13C NMR 'CD3OD, 125 MHz), d 36.5, 36.8,
4.1.12. 2-Fluorodehydrocoelenterazine 313c). 13c was
synthesized according to the same procedures described in
13a. 13c '107 mg) in 77% yield from 12c '140 mg,
0.33 mmol) and manganese'II) oxide '1.23 g, 1.3 mmol).
Compound 13c: UV 'MeOH/H2O1/2) lmax 'log 1), 546
1
'0.24), 353 '1.07), 280 '1.69) nm. H NMR 'DMSO-d6,
71.8, 72.1, 75.2, 75.5, 101.9, 108.7, 115.5, 116.1 'd, JC±F
500 MHz), d 4.28 '2H, s), 6.80 '2H, d, J8.3 Hz), 7.23
22.8 Hz), 116.9, 125.3, 128.2, 129.5, 129.8, 130.0, 130.1,