into amino acids using standard protocol benzotriazole method-
ology.
2-(2-(6-Chloro-1,3-dioxo-1H-benzo[f ]isoindol-2(3H)-
yl)acetamido)acetic acid (23)
2-(2-(1H-Benzo[d][1,2,3]triazol-1-yl)-2-oxoethyl)-6-chloro-1H-
benzo[f ]isoindole-1,3(2H)-dione (21) (480 mg, 1.2 mmol) in THF
(5 mL) was added dropwise into a solution of glycine (110 mg,
1.4 mmol) and triethylamine (120 mg, 1.2 mmol) in acetonitrile–
water (7 : 3) and was stirred for 1 h at room temperature. To the
reaction mixture aqueous 4 M HCl (1 mL) was added and the
solvent was removed under vacuum. The residue was dissolved in
ethyl acetate (30 mL) and washed twice with 4 M HCl (20 mL ¥ 2)
and twice with saturated NaCl solution (20 mL ¥ 2). The solvent
was evaporated to give the pure 2-(2-(6-chloro-1,3-dioxo-1H-
benzo[f ]isoindol-2(3H)-yl)acetamido)acetic acid (23) (320 mg,
76%). mp 272–273 ◦C. 1H NMR (300 MHz, DMSO-d6): d 8.63–
8.61 (m, 2H), 8.55 (s, 1H), 8.43 (s, 1H), 8.32 (d, J = 8.7 Hz, 1H),
Experimental
2-(6-Chloro-1,3-dioxo-1H-benzo[f ]isoindol-2(3H)-yl)acetic
acid (15)
Glycine (160 mg, 2.14 mmol) and triethylamine (22 mg, 0.214
mmol) were added to p-chloronaphtho[2,3-c]furan-1,3-dione (11)
(500 mg, 2.14 mmol) in toluene (30 mL) and heated under
reflux for 4 h. The precipitate was filtered off and washed
with dichloromethane to give the pure 2-(6-chloro-1,3-dioxo-1H-
benzo[f ]isoindol-2(3H)-yl)acetic acid (15) (550 mg, 91%). mp 307–
◦
1
308 C. H NMR (300 MHz, DMSO-d6): d 8.63 (s, 1H), 8.56 (s,
1H), 8.43 (s, 1H), 8.32 (d, J = 8.5 Hz, 1H), 7.84 (d, J = 8.5 Hz,
1H), 4.32 (s, 2H). 13C NMR (75 MHz, DMSO-d6): d 168.9, 166.7,
166.5, 136.0, 134.3, 133.6, 132.4, 129.9, 129.0, 128.2, 127.5, 125.0,
124.1, 32.3. Anal. Calcd for C14H8ClNO4: C, 58.05; H, 2.78; N,
4.84; Found C, 57.70; H, 2.63; N, 4.67%.
7.83 (d, J = 8.7 Hz, 1H), 4.31 (s, 2H), 3.79 (d, J = 5.7 Hz, 2H). 13
C
NMR (75 MHz, DMSO-d6): d 170.9, 166.9, 166.3, 136.0, 134.1,
133.5, 132.3, 129.8, 129.0, 128.7, 128.0, 124.6, 123.8, 40.8, 40.3.
Anal. Calcd for C16H11ClN2O5: C, 55.43; H, 3.20; N, 8.08; Found
C, 55.26; H, 3.53; N, 7.89%.
2-(7-Chloro-3-(diethylcarbamoyl)-2-naphthamido)acetic acid (19)
2-(((9H-Fluoren-9-yl)methoxy)carbonylamino)-6-(2-(6-chloro-1,3-
dioxo-1H-benzo[f ]isoindol-2(3H)-yl)acetamido)hexanoic acid (24)
Diethylamine (190 mg, 2.56 mmol) was added to 2-(6-chloro-
1,3-dioxo-1H-benzo[f ]isoindol-2(3H)-yl)acetic acid (15) (500 mg,
1.7 mmol) in DMF (10 mL) and refluxed for 1 h. The
solution was cooled and 2-(7-chloro-3-(diethylcarbamoyl)-2-
naphthamido)acetic acid (19) precipitated and was washed with
dichloromethane. (400 mg, 73%). mp 238–239 ◦C. 1H NMR
(300 MHz, DMSO-d6): d 9.30 (br s, 1H), 8.53 (s, 1H), 8.51 (s,
1H), 8.38 (s, 1H), 8.27 (d, J = 8.7 Hz, 1H), 7.78 (dd, J = 8.7 Hz,
J = 2.1 Hz, 1H), 3.96 (d, J = 6 Hz, 2H), 2.95–2.75 (m, 4H), 1.40–
1.05 (m, 6H). 13C NMR (75 MHz, DMSO-d6): d 168.2, 167.4,
167.2, 136.0, 134.0, 133.7, 132.4, 129.7, 129.3, 129.0, 128.6, 124.2,
123.5, 42.2, 41.3, 11.4. Anal. Calcd for C18H19ClN2O4: C, 59.59;
H, 5.28; N, 7.72; Found C, 59.31; H, 5.32; N, 7.65%.
2-(2-(1H-Benzo[d][1,2,3]triazol-1-yl)-2-oxoethyl)-6-chloro-1H-
benzo[f ]isoindole-1,3(2H)-dione (21) (350 mg, 0.9 mmol) in THF
(5 ml) was added dropwise to a solution of Fmoca-Lysine-OH·HCl
(360 mg, 0.9 mmol) and triethylamine (180 mg, 1.8 mmol) in
acetonitrile–water (7 : 3) and the mixture was stirred for 1 h at
room temperature. To the reaction mixture aqueous HCl (1 mL,
4 M) was added and the solvent was removed under vacuum.
The residue was dissolved in ethyl acetate (30 ml) and washed
twice with 4 M HCl (20 mL ¥ 2) and saturated NaCl solution
(20 mL ¥ 2). The solvent was dried and evaporated to give
the pure 2-(((9H-fluoren-9-yl)methoxy)carbonylamino)-6-(2-
(6-chloro-1,3-dioxo-1H-benzo[f ]isoindol-2(3H)-yl)acetamido)-
◦
1
hexanoic acid (24) (420 mg, 72%). mp 246–247 C. H NMR
(300 MHz, DMSO-d6): d 8.58 (s, 1H), 8.52 (s, 1H), 8.40 (s, 1H),
8.30 (d, J = 8.7 Hz, 1H), 7.87 (d, J = 7.5 Hz, 2H), 7.80 (dd,
J = 8.7 Hz, J = 2.0 Hz, 1H), 7.72 (d, J = 7.5 Hz, 2H), 7.63 (s,
J = 7.7 Hz, 1H), 7.41 (t, J = 7.5 Hz, 2H), 7.34–7.30 (m, 3H),
2-(2-(1H-Benzo[d][1,2,3]triazol-1-yl)-2-oxoethyl)-6-chloro-1H-
benzo[f ]isoindole-1,3(2H)-dione (21)
Thionyl chloride (220 mg, 1.9 mmol) was added to benzo-
triazole (820 mg, 6.8 mmol) in THF (10 mL) at 0 ◦C. The
mixture was stirred for 40 min. 2-(6-Chloro-1,3-dioxo-1H-
benzo[f ]isoindol-2(3H)-yl)acetic acid (15) (500 mg, 1.7 mmol)
was then added slowly and followed by stirring for an ad-
ditional 2 h at room temperature. The solvent was evapo-
rated and dichloromethane was added to the residue. Undis-
solved solid was filtered off and the solution was washed
with saturated sodium carbonate (25 mL ¥ 2) and sodium
chloride solution (25 mL ¥ 2). The solvent was evaporated
to give pure 2-(2-(1H-benzo[d][1,2,3]triazol-1-yl)-2-oxoethyl)-6-
chloro-1H-benzo[f ]isoindole-1,3(2H)-dione (21) (560 mg, 85%).
mp 245–246 ◦C. 1H NMR (300 MHz, DMSO-d6): d 8.71 (s, 1H),
8.64 (s, 1H), 8.46 (s, 1H), 8.36–8.31 (m, 2H), 8.18 (d, J = 8.1 Hz,
4.28–4.24 (m, 4H), 3.92 (s, 1H), 3.08 (s, 2H), 1.2-1.8 (m, 6H). 13
C
NMR (75 MHz, DMSO-d6): d 173.9, 166.9, 166.8, 165.6, 156.1,
143.7, 140.6, 135.8,133.9, 133.4, 132.2, 129.6, 128.9, 128.6, 127.9,
127.6, 127.0, 125.2, 124.4, 123.7, 120.0, 65.6, 53.7, 46.6, 40.4, 38.5,
30.3, 28.5, 23.0. Anal. Calcd for C35H30ClN3O7·H2O: C, 63.88; H,
4.90; N, 6.38; Found C, 63.97; H, 4.33; N, 6.51%.
Acknowledgements
We thank Dr Kirk Shanze and Dr Katsu Ogawa (University of
Florida) for help with UV and fluorescence measurements.
1H), 7.88–7.80 (m, 2H), 7.66 (t, J = 7.5 Hz, 1H), 5.62 (s, 2H). 13
C
Notes and references
NMR (75 MHz, DMSO-d6): d 166.7, 166.4, 145.6, 136.2, 134.5,
133.8, 132.6, 131.5, 130.7, 130.2, 129.3, 128.3, 127.6, 127.1, 125.4,
124.6, 120.6, 113.8, 41.3. Anal. Calcd for C20H11ClN4O3: C, 61.47;
H, 2.84; N, 14.34; Found C, 61.45; H, 2.69; N, 13.96%.
1 J. Zhang, R. E. Campbell, A. Y. Ting and R. Y. Tsien, Nat. Rev. Mol.
Cell Biol., 2002, 3, 906–918.
2 G. Grynkiewicz, M. Poenie and R. Y. Tsien, J. Biol. Chem., 1985, 260,
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The Royal Society of Chemistry 2010
Org. Biomol. Chem., 2010, 8, 1296–1300 | 1299
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