Molecules 2019, 24, 294
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3.3.2. Diethyl-[(2-hydroxyphenyl)(phenyl)methyl]phosphonate (2e)
According to the general procedure, a mixture of 1,3-benzoxazine 1e (0.20 g, 0.66 mmol),
triethylphosphite (0.11 g, 0.66 mmol, 0.11 mL) and boron trifluoride etherate (0.01 g, 0.13 mmol,
0.01 mL) in acetonitrile (5 mL) was reacted. After purification 2e (0.08g, 40%) was obtained as a white
solid, m.p. = 157–159 ◦C. 1H-NMR (CDCl3, 400 MHz):
δ
1.12 (t, J = 7.2 Hz, 3H), 1.15 (t, J = 7.2 Hz,
3H), 3.74-4.16 (m, 4H), 4.72 (d, J = 26.6 Hz, 1H), 6.78-7.53 (m, 9H). 13C-NMR (CDCl3, 100 MHz):
16.3,
18.3, 47.0 (d, 1JC-P = 136.2 Hz), 63.5 (d, 2JC-P = 7.0 Hz), 64.0 (d, 2JC-P = 7.4 Hz), 119.5, 121.0, 123.7, 129.1,
δ
129.5, 129.7, 130.0, 131.1, 131.2, 132.5, 137.2, 155.3. 31P-NMR (CDCl3, 161.90 MHz):
(CI+): calculated for C17H21O4P [M + H]+, m/z 321.1256; found for [M + H]+, m/z 321.1306.
δ 28.78. HRMS
3.3.3. Diethyl-[(2-hydroxyphenyl)(p-tolyl)methyl]phosphonate (2g)
According to the general procedure, a mixture of 1,3-benzoxazine 1g (0.10 g, 0.31 mmol), triethyl
phosphite (0.05 g, 0.31 mmol, 0.05 mL) and boron trifluoride etherate (0.009 g, 0.06 mmol, 0.009 mL) in
acetonitrile (3 mL) was reacted. After purification 2g (0.04 g, 30%) was obtained as a white solid, m.p.
= 151–153 ◦C. 1H-NMR (CDCl3, 400 MHz):
δ
1.13 (t, J = 7.2 Hz, 3H), 1.16 (t, J = 7.2 Hz, 3H), 2.32 (s, 3H),
3.88 (m, 2H), 4.03 (m, 2H), 4.69 (d, J = 26.4 Hz, 2H), 6.79-7.39 (m, 8H). 13C-NMR (CDCl3, 100 MHz):
16.3, 21.2, 47.3 (d, 1JC-P = 136.2 Hz), 63.4, 64.0, 119.5, 121.0, 123.7, 129.1, 129.5, 129.7, 130.0, 131.1, 131.2,
132.5, 137.2, 155.3. 31P-NMR (CDCl3, 161.90 MHz): 28.78. HRMS (CI+): calculated for C18H23O4P [M
+ H]+, m/z 335.1412; found for [M + H]+, m/z 335.1419.
δ
δ
3.3.4. Diethyl{[benzyl(2-hydroxybenzyl)amino]methyl}phosphonate (3a)
According to the general procedure, a mixture of 1,3-benzoxazine 1a (0.20 g, 0.88 mmol),
triethylphosphite (0.16 g, 0.88 mmol, 0.15 mL), and boron trifluoride etherate (0.02 g, 0.17 mmol,
0.02 mL), in acetonitrile (5 mL) was reacted. After purification 3a (0.28g, 89%) was obtained as a
colorless oil 1H-NMR (CDCl3, 200 MHz):
δ
1.29 (t, J = 7.0 Hz, 3H), 2.87 (d, J = 11.6 Hz, 2H), 3.75 (s, 2H),
3.95, (s, 2H), 4.05 (dq, J = 7.2, 7.2 Hz, 4H), 6.72–7.33 (m, 9H). 13C-NMR (CDCl3, 50 MHz):
16.5, 16.6,
47.9 (d, 1JC-P = 158.3 Hz), 58.8 (d, J = 6.4 Hz), 59.1 (d, J = 9.9 Hz), 62.2, 62.4, 116.5, 119.5, 121.9, 127.9,
δ
128.7, 129.3, 129.6, 129.9, 136.6, 157.4. 31P-NMR (CDCl3, 80.9 MHz):
for C19H26NO4P [M + H]+, m/z 364.1679; found for [M + H]+, m/z 364.1724.
δ
21.92. HRMS (CI+): calculated
3.3.5. Diethyl{benzyl[1-(2-hydroxyphenyl)-2-methylbutyl]amino}methyl)phosphonate (3d)
According to the general procedure, a mixture of 1,3-benzoxazine 1d, (0.20 g, 0.83 mmol),
triethylphosphite (0.15 g, 0.83 mmol, 0.14 mL) and boron trifluoride etherate (0.02 g, 0.16 mmol,
0.02 mL), in acetonitrile (5 mL) were reacted. After purification 3d (0.12g, 37%) was obtained as a
1
colorless oil The compound was characterized as diastereomeric mixture. H-NMR (CDCl3, 400 MHz):
δ
0.53 (d, J = 6.8 Hz, 3H), 0.72 (dd, J = 5.2 Hz, 5.2 Hz, 3H), 0.93 (t, J = 7.2 Hz, 3H)*, 1.09 (d, J = 6.8 Hz,
3H)*, 1.22 (t, J = 7.2 Hz, 3H, 3H*), 1.23 (t, J = 7.2 Hz, 3H, 3H*), 1.91 (dq, J = 7.2, 2.8 Hz, 2H), 1.95 (dq, J =
7.2, 2.8 Hz, 2H)*, 2.22–2.35 (m, 1H, 1H*), 3.26 (dd, J = 16.8, 3.2 Hz, 1H), 3.28 (dd, J = 16.8, 3.2 Hz, 1H)*,
3.32 (d, J = 7.6 Hz, 1H, 1H*), 3.59 (d, J = 16.0 Hz, 1H), 3.64 (d, J = 14 Hz, 2H, 2H*), 3.68 (dd, J = 14.0, 4.0
Hz, 1H)*, 4.04–4.14 (m, 2H, 2H*), 4.23–4.33 (m, 2H, 2H*), 6.89–7.33 (m, 9H, 9H*), 10.40 (s, 1H, 1H*).
13C-NMR (CDCl3, 100 MHz): 10.7, 11.2*, 16.4, 16.5, 16.6, 17.2*, 25.9, 27.3, 33.5, 33.9, 44.9 (d, 1JC-P = 121.8
Hz), 45.0 (d, 1JC-P = 122.6 Hz)*, 58.0, 62.1, 62.2*, 71.1, 71.8*, 116.9, 117.1*, 119.0, 119.1*, 122.3, 125.0*,
127.5, 127.5*, 128.5, 128.5*, 128.8, 128.9*, 129.2, 129.2*, 132.9, 138.5*, 148.0, 148.1*. 31P-NMR (CDCl3,
161.90 MHz):
δ
26.01, 26.36* HRMS (CI+): calculated for C23H34NO4P [M + H]+, m/z 420.2305; found
for [M + H]+, m/z 420.2286.
3.3.6. Diethyl((benzyl((4-chlorophenyl)(2-hydroxyphenyl)methyl)amino)methyl)phosphonate (3h)
According to the general procedure, a mixture of 1,3-benzoxazine 1h (0.20 g, 0.59 mmol),
triethylphosphite (0.10 g, 0.59 mmol, 0.1 mL) and boron trifluoride etherate (0.01 g, 0.11 mmol, 0.01 mL)