PAPER
Phosphaisocoumarin Acids
2415
1H NMR (300 MHz, CD3OD): d = 7.89–7.94 (m, 1 H), 7.78–7.85
13C NMR (75.4 MHz, CD3OD): d = 155.63, 136.76, 135.95, 131.68,
130.36, 130.17, 129.33 (d, J = 6.7 Hz), 128.80 (d, J = 5.7 Hz),
128.69, 125.63 (d, J = 12.4 Hz), 123.79 (d, J = 181.4 Hz), 114.00
(d, J = 15.5 Hz).
MS (EI, 70 eV): m/z (%) = 292 (M+, 70), 258 (66), 196 (61), 105
(100), 77 (76).
(m, 3 H), 7.70–7.74 (m, 1 H), 7.48–7.50 (m, 3 H).
13C NMR (125.7 MHz, CD3OD): d = 149.28, 135.67, 135.31 (d,
J = 19.6 Hz), 135.01, 133.55, 130.89, 130.34, 129.90 (d, J = 13.7
Hz), 129.06, 128.98 (d, J = 178.8 Hz), 128.45 (d, J = 9.8 Hz),
114.01.
MS (EI, 70 eV): m/z (%) = 326 (M+, 100), 233 (5), 199 (7), 163 (15),
HRMS-EI: m/z calcd for C14H10ClO3P [M+]: 292.0051; found:
105 (53), 77 (65).
292.0052.
HRMS-EI: m/z calcd for C14H9Cl2O3P [M+]: 325.9661; found:
325.9660.
2i
Pale yellow solid; mp 202–204 °C.
2e
IR (KBr): 3398, 2921, 1581, 1272, 1054, 870 cm–1.
Pale yellow solid; mp 222–223 °C.
IR (KBr): 3428, 2924, 1599, 1226, 1065, 1030, 997 cm–1.
1H NMR (300 MHz, CD3OD): d = 7.91–7.97 (m, 1 H), 7.71–7.74
(m, 2 H), 7.47–7.51 (m, 3 H), 7.30–7.41 (m, 2 H), 3.95 (s, 3 H).
13C NMR (125.7 MHz, CD3OD): d = 161.28 (d, J = 19.6 Hz),
147.57, 136.26, 131.49 (d, J = 11.7 Hz), 130.71, 130.59, 129.87,
129.03, 126.22 (d, J = 178.1 Hz), 120.06, 113.66 (d, J = 9.8 Hz),
105.22 (d, J = 13.7 Hz), 56.29.
1H NMR (300 MHz, CD3OD): d = 7.31–7.97 (m).
13C NMR (75.4 MHz, CD3OD): d = 150.53 (d, J = 8.2 Hz), 137.46
(d, J = 4.2 Hz), 133.54 (d, J = 5.1 Hz), 131.68, 130.66, 130.13,
129.26 (d, J = 5.5 Hz), 128.77 (d, J = 4.3 Hz), 128.61, 128.20 (d,
J = 8.6 Hz), 123.30 (d, J = 177.6 Hz), 104.59 (d, J = 5.3 Hz).
MS (EI, 70 eV): m/z (%) = 336 (M+, 4), 277 (100), 258 (55), 196
(22), 105 (38), 77 (49).
HRMS-EI: m/z calcd for C14H10BrO3P [M+]: 335.9545; found:
335.9546.
MS (EI, 70 eV): m/z (%) = 366 (M+, 100), 351 (37), 288 (31), 163
(17), 105 (45), 77 (72).
2-Phenylethynylphenylphosphonic Acid Dimethyl Ester (6)
To a mixture of 2-hydroxyphenylphosphonic dimethyl ester (5; 1.01
g, 5.0 mmol) and nonafluorobutanesulfonyl fluoride (2.1 g, 7.0
mmol) was added dropwise Et3N (5 mL) at 0 °C. After stirring at r.t.
for 8 h, the mixture was concentrated in vacuo and the residue was
then dissolved in H2O (15 mL) and extracted with EtOAc (3 × 30
mL). The combined organic extracts were washed with brine (50
mL), dried (Na2SO4), and evaporated in vacuo to give the corre-
sponding nonaflate, which was used directly in the following step
without further purification. To a mixture of the above nonaflate
(2.17 g, 4.5 mmol), PdCl2(PPh3)2 (105 mg, 0.15 mmol), Et3N
(2.02 g, 20 mmol), CuI (95 mg, 0.50 mmol), and DMF (15 mL) was
added dropwise phenylacetylene (759 mg, 7.5 mmol) at r.t. After
stirring at 45 °C for 7 h under N2, the mixture was diluted with
EtOAc (60 mL). The organic layer was separated and washed with
aq NH4Cl until neutral. It was then washed with brine (30 mL),
dried (Na2SO4), and evaporated in vacuo. The residue was chro-
matographed on silica gel using hexane–EtOAc (5:1 to 2:1) as elu-
ent to give the corresponding product 6 as a yellow oil; yield: 615
mg (43%, overall yield for the two steps).
HRMS-EI: m/z calcd for C15H12BrO4P [M+]: 365.9651; found:
365.9686.
2f
Pale yellow solid; mp 181–182 °C.
IR (KBr): 3402, 2927, 1580, 1272, 1054, 857 cm–1.
1H NMR (300 MHz, CDCl3): d = 11.45 (br s, 1 H), 7.91–7.98 (m, 1
H), 7.80 (m, 2 H), 7.54–7.86 (m, 1 H), 7.38 (m, 5 H), 6.67 (s, 1 H).
13C NMR (75.4 MHz, CDCl3): d = 150.03 (d, J = 9.4 Hz), 137.20
(d, J = 6.3 Hz), 133.16, 132.73, 129.37, 129.07 (d, J = 8.8 Hz),
128.44, 127.52 (d, J = 14.5 Hz), 126.86 (d, J = 12.3 Hz), 125.08,
121.00 (d, J = 185.6 Hz), 104.12 (d, J = 13.0 Hz).
MS (EI, 70 eV): m/z (%) = 258 (M+, 100), 240 (4), 165 (12), 105
(45), 77 (72).
HRMS-EI: m/z calcd for C14H11O3P [M+]: 258.0440; found:
258.0441.
2g
IR (KBr): 2922, 2373, 1632, 1383, 1260, 1086, 875 cm–1.
Pale yellow solid; mp 117–119 °C.
IR (KBr): 3429, 2921, 1573, 1266, 1054, 869 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.97–8.05 (m, 1 H), 7.34–7.67 (m,
8 H), 3.83 (d, J = 11.1 Hz, 6 H).
13C NMR (75.4 MHz, CDCl3): d = 134.17 (d, J = 6.3 Hz), 133.04
(d, J = 14.2 Hz), 132.01, 131.34, 128.48 (d, J = 185.3 Hz), 128.47,
128.17, 127.50 (d, J = 15.8 Hz), 125.63 (d, J = 6.7 Hz), 122.73,
94.37, 87.45, 52.72 (d, J = 5.3 Hz).
MS (EI): m/z (%) = 286 (M+, 100), 253 (35), 191 (67), 165 (43), 105
(20), 77 (21).
HRMS-EI: m/z calcd for C16H15O3P [M+]: 286.0753; found:
286.0754.
1H NMR (300 MHz, CDCl3): d = 7.78–7.90 (m, 1 H), 7.42–7.54 (m,
1 H), 7.29–7.37 (m, 1 H), 7.14–7.22 (m, 1 H), 6.76 (br s, 1 H), 5.91
(s, 1 H), 2.36–2.44 (m, 2 H), 1.58–1.70 (m, 2 H), 1.36–1.47 (m, 2
H), 0.94 (t, J = 7.2 Hz, 3 H).
13C NMR (75.4 MHz, CDCl3): d = 154.58 (d, J = 9.3 Hz), 137.35
(d, J = 9.9 Hz), 132.59, 128.96 (d, J = 12.6 Hz), 126.93 (d, J = 17.6
Hz), 125.80 (d, J = 12.1 Hz), 120.01 (d, J = 174.3 Hz), 104.69 (d,
J = 14.1Hz), 34.51, 28.47, 22.14, 13.93.
MS (EI, 70 eV): m/z (%) = 238 (M+, 100), 209 (85), 196 (100), 115
(17), 77 (12).
4-Halo-1-methoxy-3-phenylbenzo[c][1,2]oxaphosphinine 1-Ox-
ides 7a and 7b
HRMS-EI: m/z calcd for C12H15O3P [M+]: 238.0753; found:
238.0754.
The dimethyl ester 6 (858 mg, 3 mmol) and aq 1 M NaOH (18 mL,
18 mmol) were combined in MeOH (15 mL) and refluxed for 1 h.
The mixture was evaporated in vacuo to remove the MeOH, then di-
luted with H2O (20 mL), cooed in an ice bath, neutralized with con-
cd HCl, and extracted with EtOAc (5 × 20 mL). The combined
extracts were evaporated in vacuo to give the corresponding mo-
noester in 90% yield, which was used without further purification.
2h
Pale yellow solid; mp 187–189 °C.
IR (KBr): 3394, 2921, 1580, 1266, 1059, 870 cm–1.
1H NMR (300 MHz, CD3OD): d = 7.84–8.00 (m, 4 H), 7.58–7.64
(m, 1 H), 7.35–7.46 (m, 4 H).
Synthesis 2008, No. 15, 2412–2416 © Thieme Stuttgart · New York