nmax 3450, 2214, 1706, 1612, 1570, 1522, 1270, 1173; HRMS calc
1H, J = 2.4 Hz, J = 8.7 Hz), 6.83 (d, 1H, J = 2.4 Hz), 6.65 (d,
2H, J = 9.1 Hz), 4.27 (t, 2H, J = 6.6 Hz), 3.89 (s, 3H), 3.47 (m,
2H), 3.08 (s, 6H), 1.79 (m, 2H), 1.69 (m, 2H), 1.52 (m, 2H); 13C
NMR (100 MHz, CDCl3) d 164.6, 164.2, 162.0, 161.8, 156.5, 154.5,
153.5, 148.1, 134.0, 130.8, 119.3, 117.4, 114.7, 113.9, 112.4, 111.4,
100.2, 93.8, 65.6, 55.9, 39.9, 39.5, 29.0, 28.2, 23.3; IR (film) nmax
3349, 2213, 1717, 1570, 1523, 1167; HRMS calc for C28H29N3O6Na
(M+Na)+ 526.1949 found 526.1950.
for C20H27N3O4Na (M+Na)+ 396.1894 found 396.1897.
Carbamate 25b. 72% yield; dark orange solid; Rf 0.40 (2%
1
MeOH in CH2Cl2); H NMR (400 MHz, CDCl3) d 8.01 (s, 1H),
7.89 (d, 2H, J = 9.1 Hz), 6.65 (d, 2H, J = 9.1 Hz), 4.64 (bs, 1H),
4.23 (t, 2H, J = 6.6 Hz), 3.13–3.06 (m, 8H), 1.73 (m, 2H), 1.52 (m,
2H), 1.45–1.40 (m, 11H); 13C NMR (100 MHz, CDCl3) d 164.2,
155.9, 154.4, 153.4, 133.9, 119.1, 117.4, 111.3, 93.6, 78.8, 65.5,
40.2, 39.9, 29.5, 28.3, 28.1, 23.0; IR (film) nmax 3446, 2932, 2211,
1707, 1568, 1521, 1088; HRMS calc for C22H31N3O4Na (M+Na)+
424.2207 found 424.2209.
Dye 27c. 64% yield; orange solid; Rf 0.43 (2% MeOH in
1
CH2Cl2); H NMR (400 MHz, CDCl3) d 8.83 (bs, 1H), 8.77 (s,
1H), 8.05 (s, 1H), 7.92 (d, 2H, J = 9.0 Hz), 7.57 (d, 1H, J = 8.7
Hz), 6.92 (dd, 1H, J = 2.2 Hz, J = 8.7 Hz), 6.84 (d, 1H, J = 2.2 Hz),
6.67 (d, 2H, J = 9.0 Hz), 4.26 (t, 2H, J = 6.6 Hz), 3.90 (s, 3H), 3.45
(m, 2H), 3.09 (s, 6H), 1.76 (m, 2H), 1.65 (m, 2H), 1.46 (m, 4H);
13C NMR (100 MHz, CDCl3) d 164.7, 164.3, 161.9, 161.8, 156.5,
154.5, 153.5, 148.1, 134.0, 130.8, 119.3, 117.4, 114.8, 113.9, 112.4,
111.4, 100.2, 94.0, 65.8, 56.0, 40.0, 39.7, 29.3, 28.5, 26.6, 25.6; IR
(film) nmax 3349, 2214, 1713, 1616, 1567, 1525, 1167; HRMS calc
for C29H31N3O6Na (M+Na)+ 540.2105 found 540.2103.
Carbamate 25c. 78% yield; dark orange solid; Rf 0.34 (EtOAc–
1
hexanes 4 : 6); H NMR (400 MHz, CDCl3) d 7.94 (s, 1H), 7.81
(d, 2H, J = 9.0 Hz), 6.58 (d, 2H, J = 9.0 Hz), 4.73 (bs, 1H), 4.17
(t, 2H, J = 6.5 Hz), 3.00 (m, 8H), 1.65 (m, 2H), 1.46–1.27 (m,
15H); 13C NMR (100 MHz, CDCl3) d 164.0, 155.7, 154.1, 153.3,
133.7, 118.9, 117.2, 111.1, 93.3, 78.5, 65.5, 40.1, 39.7, 29.6, 28.2,
28.1, 26.1, 25.3; IR (film) nmax 2933, 2203, 1706, 1571, 1521, 1270,
1063; HRMS calc for C23H33N3O4Na (M+Na)+ 438.2363 found
438.2366.
Dye 27d. 78% yield; orange solid; Rf 0.34 (EtOAc–hexanes
1 : 1); 1H NMR (400 MHz, CDCl3) d 8.81 (s, 1H), 8.75 (bs, 1H),
8.03 (s, 1H), 7.91 (d, 2H, J = 9.0 Hz), 7.56 (d, 1H, J = 8.7 Hz),
6.91 (dd, 1H, J = 2.3 Hz, J = 8.7 Hz), 6.84 (d, 1H, J = 2.3 Hz),
6.66 (d, 2H, J = 9.0 Hz), 4.24 (t, 2H, J = 6.7 Hz), 3.89 (s, 3H),
3.43 (m, 2H), 3.08 (s, 6H), 1.72 (m, 2H), 1.60 (m, 2H), 1.36 (m,
8H); 13C NMR (100 MHz, CDCl3) d 164.6, 164.3, 161.8, 161.8,
156.5, 154.4, 153.4, 148.0, 134.0, 130.8, 119.3, 117.4, 114.8, 113.9,
112.4, 111.4, 100.2, 93.9, 65.9, 55.9, 40.0, 39.7, 29.3, 29.1, 29.1,
28.5, 26.9, 25.7; IR (film) nmax 3356, 2214, 1713, 1570, 1525, 1370,
1176; HRMS calc for C31H35N3O6Na (M+Na)+ 568.2418 found
568.2415.
Carbamate 25d. 73% yield; dark orange solid; Rf 0.38 (EtOAc–
1
hexanes 4 : 6); H NMR (400 MHz, CDCl3) d 8.03 (s, 1H), 7.90
(d, 2H, J = 9.0 Hz), 6.66 (d, 2H, J = 9.0 Hz), 4.57 (bs, 1H), 4.23 (t,
2H, J = 6.7 Hz), 3.08 (s, 8H), 1.70 (m, 2H), 1.41 (m, 13H), 1.30 (m,
6H); 13C NMR (100 MHz, CDCl3) d 164.2, 155.9, 154.4, 153.4,
133.9, 119.2, 117.4, 111.4, 93.8, 78.8, 65.8, 40.5, 39.9, 29.9, 29.0,
28.5, 28.3, 26.6, 25.7; IR (film) nmax 3461, 2203, 1735, 1713, 1570,
1266, 1103; HRMS calc for C25H37N3O4Na (M+Na)+ 466.2676
found 466.2679.
General procedure for the synthesis of ratiometric dye 27.
A
TFA solution was prepared by combining 5 ml of TFA with
0.1 ml of anisole in 4.9 ml of DCM. 2.76 ml of this solution
were added to 25 (0.286 mmol) and the reaction was left stirring
at room temperature. After 30 min, reaction was completed
and the solution was concentrated, rinsed with toluene (4 ¥
10 ml), concentrated again, and dried under high vacuum to
yield compound 26. To a round bottom flask containing 26 in
dry DCM (2 ml), DMAP (0.029 mmol), 9 (0.272 mmol), and
DIPEA (0.572 mmol) were added. The reaction was left stirring
overnight at room temperature. Upon completion, the reaction
was concentrated and purified via flash chromatography (10–20%
ethyl acetate in hexane).
Ratiometric dye 28. To a round bottom flask containing
compound 26a (0.669 mmol) (prepared as described for the
synthesis of 27) dissolved in dry DCM (5.6 ml); DMAP (8 mg,
0.067 mmol), 9 (213 mg, 0.736 mmol), and DIPEA (0.2 ml,
1.339 mmol) were added and left stirring overnight at room
temperature. Upon completion, the reaction was concentrated
under reduced pressure and purified via flash chromatography
(0–7% MeOH–DCM) to yield dye 28 (163 mg, 53%). 28: red solid;
Rf 0.33 (3% MeOH in CH2Cl2); 1H NMR (400 MHz, DMSO-d6)
d 8.74 (bs, 2H), 8.04 (s, 1H), 7.87 (d, 2H, J = 9.1 Hz), 7.76 (d, 1H,
J = 8.6 Hz), 6.84 (dd, 1H, J = 2.1 Hz, J = 8.6 Hz), 6.76 (d, 2H, J =
9.1 Hz), 6.73 (d, 1H, J = 2.1 Hz), 4.28 (t, 2H, J = 6.1 Hz), 3.46 (m,
2H), 3.07 (s, 6H), 1.94 (m, 2H); 13C NMR (100 MHz, DMSO-d6) d
163.9, 163.7, 161.9, 161.1, 156.4, 154.1, 153.8, 148.0, 133.8, 132.0,
118.2, 117.6, 114.5, 113.6, 111.7, 111.1, 101.9, 92.1, 64.0, 36.6,
28.3; IR (film) nmax 3201, 2211, 1709, 1567, 1522, 1168; HRMS
calc for C25H23N3O6Na (M+Na)+ 484.1479 found 484.1481.
Dye 27a. 69% yield; orange solid; Rf 0.41 (2% MeOH in
1
CH2Cl2); H NMR (400 MHz, CDCl3) d 8.90 (bs, 1H), 8.83 (s,
1H), 8.07 (s, 1H), 7.92 (d, 2H, J = 9.0 Hz), 7.56 (d, 1H, J = 8.7
Hz), 6.92 (dd, 1H, J = 2.4 Hz, J = 8.7 Hz), 6.84 (d, 1H, J = 2.4 Hz),
6.67 (d, 2H, J = 9.0 Hz), 4.38 (t, 2H, J = 6.2 Hz), 3.91 (s, 3H), 3.61
(m, 2H), 3.11 (s, 6H), 2.09 (m, 2H); 13C NMR (100 MHz, CDCl3) d
164.7, 164.3, 162.2, 161.8, 156.6, 154.7, 153.5, 148.2, 134.1, 130.9,
119.3, 117.4, 114.8, 114.0, 112.4, 111.4, 100.2, 93.7, 63.4, 56.0,
40.0, 36.7, 28.7; IR (film) nmax 3349, 2208, 1706, 1612, 1557, 1522,
1173; HRMS calc for C26H25N3O6Na (M+Na)+ 498.1636 found
498.1638.
Ratiometric dye 29. In a round bottom flask, containing
10 (35 mg, 0.100 mmol) dissolved in DCM (0.85 ml), 26a
(38.0 mg, 0.100 mmol), DMAP (1 mg, 0.010 mmol), and DIPEA
(40 ml, 0.200 mmol) were added. The reaction was left stirring at
room temperature until completion, concentrated under reduced
pressure and purified via flash chromatography (0.25–1% MeOH–
DCM) to yield 29 (50 mg, 98%). 29: yellow solid; Rf 0.42 (3%
MeOH in CH2Cl2); 1H NMR (400 MHz, CDCl3) d 8.85 (bs, 1H),
8.76 (s, 1H), 8.06 (s, 1H), 7.90 (d, 2H, J = 9.1 Hz), 7.63 (s, 1H),
Dye 27b. 74% yield; orange solid; Rf 0.43 (2% MeOH in
1
CH2Cl2); H NMR (400 MHz, CDCl3) d 8.80 (bs, 2H), 8.03 (s,
1H), 7.90 (d, 2H, J = 9.1 Hz), 7.55 (d, 1H, J = 8.7 Hz), 6.91 (dd,
3538 | Org. Biomol. Chem., 2011, 9, 3530–3540
This journal is
The Royal Society of Chemistry 2011
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