PRACTICAL SYNTHETIC PROCEDURES
Synthesis of Dialkyl Phosphates
Didodecyl Phosphate
Yield: 57.8 g (74%); colourless solid; mp 54–55 °C (Lit. mp 56–
58 °C).
2517
31P NMR: δ = –0.4.
2
1
Dipentyl Phosphate
Yield: 34.3 g (80%); colourless liquid.
1H NMR: δ = 0.91 (t, J = 7 Hz, 6 H), 1.32–1.40 (m, 8 H), 1.68 (quint,
J = 7 Hz, 4 H), 4.01 (q, J = 7 Hz, 4 H), 9.72 (s, 1 H, OH).
13C NMR: δ = 13.7, 22.0, 27.4, 29.7 (d, J = 7 Hz), 67.3 (d, J = 6 Hz).
1H NMR: δ = 0.88 (t, J = 7 Hz, 6 H), 1.25–1.40 (m, 36 H), 1.67
(
quint, J = 7 Hz, 4 H), 4.01 (q, J = 7 Hz, 4 H), 9.60 (br s, 1 H, OH)
10
(Lit. ).
13
C NMR: δ = 14.1, 22.7, 25.4, 29.2, 29.4, 29.54, 29.60, 29.64,
1
0
31P NMR: δ = +0.2.
29.66, 30.2 (d, J = 7 Hz), 31.9, 67.7 (d, J = 6 Hz) (Lit. ).
31P NMR: δ = +1.0 (Lit.10).
–
+
HRMS (ES ): m/z [M – H ] calcd for C H O P: 237.1256; found:
10
22
4
237.1247.
+
+
HRMS: (CI ): m/z [M + H ] calcd for C H O P: 435.3603; found:
2
4
52
4
4
35.3594.
Dihexyl Phosphate
Yield: 37.8 g (79%); colourless liquid.
Dihexyl Phosphite
1
A mixture of diethyl phosphite (13.81 g, 0.1 mol), hexan-1-ol
(25.54 g, 0.25 mol), and NaH (0.24 g, 0.01 mol) was heated in a
flask set up for distillation at 160 °C for 3 h. During this time, EtOH
steadily distilled over. The remaining hexane and EtOH were then
removed by vacuum distillation (Kugelrohr) to leave a residue of di-
hexyl phosphite (22.4 g, 89%) as a colourless liquid.
H NMR: δ = 0.89 (t, J = 7 Hz, 6 H), 1.24–1.47 (m, 12 H), 1.59–1.74
8
(m, 4 H), 4.02 (q, J = 7 Hz, 4 H, OCH ), 10.25 (s, 1 H, OH) (Lit. ).
2
1
3
C NMR: δ = 13.8, 22.4, 24.9, 30.0 (d, J = 6 Hz), 31.2, 67.4 (d, J =
Hz) (Lit. ).
8
6
31P NMR: δ = +0.2.
–
+
1
HRMS (ES ): m/z [M – H ] calcd for C H O P: 265.1569; found:
H NMR: δ = 0.90 (t, J = 7 Hz, 6 H), 1.26–1.44 (m, 12 H), 1.64–1.75
12
26
4
1
265.1571.
(m, 4 H), 4.07 (q, J = 8 Hz, 4 H), 6.80 (d, J = 693 Hz, 1 H).
P-H
13C NMR: δ = 13.7, 22.3, 25.0, 30.1 (d, J = 6 Hz), 31.1, 64.6 (d, J =
Bis(2-ethylbutyl) Phosphate
6
Hz).
Yield: 39.3 g (82%); colourless liquid.
1H NMR: δ = 0.90 (t, J = 7 Hz, 12 H), 1.29–1.57 (m, 10 H), 3.94 (t,
31P NMR: δ = +7.6.
J = 6 Hz, 4 H), 10.65 (s, 1 H, OH).
13C NMR: δ = 10.8, 22.6, 41.5 (d, J = 7 Hz), 69.0 (d, J = 7 Hz).
31P NMR: δ = +0.4.
Dihexyl Phosphate
By Oxidation of Dihexyl Phosphite: Dihexyl phosphite (12.5 g, 50
mmol) was stirred in a cooling bath and the temperature maintained
below 35 °C while NO was bubbled through it from a cylinder for
1.5 h. After this time, N was bubbled through the resulting green
liquid for 2 h. This gave dihexyl phosphate (12.9 g, 97%) as a faintly
yellow liquid. For spectroscopic data, see above.
2
–
+
HRMS (ES ): m/z [M – H ] calcd for C H O P: 265.1569; found:
12
26
4
2
265.1573.
Dioctyl Phosphate
Yield: 53.9 g (93%); colourless liquid.
1H NMR: δ = 0.88 (t, J = 7 Hz, 6 H), 1.22–1.48 (m, 20 H), 1.67 Acknowledgment
(
quint, J = 7 Hz, 4 H), 4.02 (q, J = 7 Hz, 4 H), 10.53 (s, 1 H).
13C NMR: δ = 13.9, 22.5, 25.3, 29.0, 29.1, 30.1 (d, J = 7 Hz), 31.7,
7.4 (d, J = 6 Hz).
We thank SynOil Inc. for their generous support of this work.
6
31P NMR: δ = +0.4.
–
References
+
HRMS (ES ): m/z [M – H ] calcd for C H O P: 321.2195; found:
(1) Smith, K. W.; Persinski, L. J. US Patent 5417287, 1995;
Chem. Abstr. 1995, 123, 87963.
16
34
4
321.2188.
(
2) Mesher, S. T.; Collett, C. PCT Int. Appl. WO 2010/022496,
010; Chem. Abstr. 2010, 152, 339215.
Bis(2-ethylhexyl) Phosphate
2
Yield: 49.3 g (85%); colourless liquid.
(3) Huddleston, D. A. US Patent 5110485, 1992; Chem. Abstr.
1992, 117, 154297.
1H NMR: δ = 0.83–0.97 (m, 12 H), 1.22–1.48 (m, 16 H), 1.52–1.65
(
m, 2 H), 3.90–4.00 (m, 4 H), 9.12 (s, 1 H, OH).
(4) Woodstock, W. H. US Patent 2402703, 1946; Chem. Abstr.
1946, 40, 27725.
(5) Mesher, S. T. E. US Patent 6039865, 2000; US Patent Appl.
13
C NMR: δ = 10.6, 13.8, 22.8, 23.0, 28.7, 29.7, 39.9 (d, J = 8 Hz),
1
8
6
9.2 (d, J = 6 Hz) (Lit. ).
2
003/0024855, 2003; Chem. Abstr. 2000, 132, 210047.
31P NMR: δ = +0.4 (Lit.19).
(
6) (a) Lukocs, B.; Mesher, S.; Wilson, T. P.; Garza, T.;
Mueller, W.; Zamora, F.; Gatlin, L. W. Canadian Patent
2552657, 2006, US Patent Appl. 2007/0173413; Chem.
Abstr. 2007, 147, 192514. (b) Funkhouser, G. P. US Patent
–
+
HRMS (ES ): m/z [M – H ] calcd for C H O P: 321.2195; found:
3
16
34
4
21.2198.
Didecyl Phosphate
Yield: 50.3 g (74%); colourless solid; mp 47–48 °C (Lit. mp 44–
4
7066262, 2006; Chem. Abstr. 2006, 144, 256872.
2
0
(
7) Quaedflieg, P. J. L. M.; Timmers, C. M.; van der Marel, G.
A.; Kuyl-Yeheskiely, E.; van Boom, J. H. Synthesis 1993,
627.
6 °C).
1
H NMR: δ = 0.88 (t, J = 7 Hz, 6 H), 1.22–1.42 (m, 28 H), 1.62–1.72
8
,18
(m, 4 H), 4.01 (q, J = 7 Hz, 4 H), 7.27 (s, 1 H, OH) (Lit. ).
(8) Wu, P.-L.; Chen, J.-H.; Huang, D.-S. J. Chin. Chem. Soc.
1999, 46, 967; Chem. Abstr. 2000, 132, 166275.
(9) Kunitake, T.; Okahata, Y. Bull. Chem. Soc. Jpn. 1978, 51,
13
C NMR: δ = 14.0, 22.6, 25.4, 29.1, 29.3, 29.4, 29.5, 30.1 (d, J = 7
8,20
Hz), 31.9, 67.6 (d, J = 6 Hz) (Lit. ).
31P NMR: δ = +1.4 (Lit.20).
1
877.
(
10) Dewa, T.; Asai, T.; Nango, M.; Oku, N. US Patent 0094020,
–
+
HRMS (ES ): m/z [M – H ] calcd for C H O P: 377.2821; found:
2010; Chem. Abstr. 2010, 152, 453842.
20
42
4
377.2822.
(11) Grosse-Ruyken, H.; Uhlig, K. J. Prakt. Chem. 1962, 18, 287.
©
Georg Thieme Verlag Stuttgart · New York
Synthesis 2012, 44, 2515–2518