PHOSPHORUS, SULFUR, AND SILICON AND THE RELATED ELEMENTS
7
3
3
7.4 Hz, 4H, para-CH); 7.68 (dd, JHH ¼ 7.5 Hz, JHP ¼12.0 Hz, C15H18NOP: C, 69.48; H, 7.00; N, 5.40; P, 11.95. Found: C,
8H, ortho-CH). 13C NMR (150.925 MHz): d ¼ 21.4, 21.9 (two
69.29; H, 7.11; N, 5.42; P, 12.00%.
dd, J ¼ 2J ¼ 31.4 Hz, PCH2, two conforms); 128.9 (two
P
P
3
overlapping d, J ¼ 5.9 Hz, meta-CH); 130.8 (two overlap-
P
2
2-Butylaminoethyldiphenylphosphine oxide (7)
ping d, J ¼ 4.8 Hz, ortho-CH); 131.9 (m, ipso-C); 132.1 (s,
P
para-CH). 31P NMR (121.56 MHz): d ¼ 32.8. ESI-MS: m/z (Irel,
2-Butylaminoethyldiphenylphosphine oxide (7) was synthe-
sized according to the general procedure using phosphine
oxide 3 (6.0 g, 18.6 mmol), 13.6 g (18 mL, 186.0 mmol) butyl-
amine, 50% aqueous solution of KOH (1.6 g, 27.9 mmol)
and DMSO (15 mL) (70 ꢀC, 1 h). The resulting residue was
purified by column chromatography on silica gel
(CHCl3–MeOH, 20:2). Yield: 5.0 g (89%); m.p.: 66.5–68 ꢀC
(c-hexane). Literature m.p. 64–65 ꢀC.[25] 1H NMR
%): 431 (20) [Mþ H]þ, 453 (100) [MþNa]þ.
General procedure for the synthesis of 2-substituted
ethyldiphenylphosphine oxides 6–12
A mixture of 2-phenoxyethyldiphenylphosphine oxide 3
(10 mmol), the corresponding nucleophilic reagent
(10–100 mmol), and KOH (15 mmol) (50% aqueous solution
or solid) in DMSO (15 mL) was vigorously stirred at
3
(300.28 MHz): d ¼ 0.84 (t, JHH ¼ 7.2 Hz, 3H, CH3); 1.25
3
3
(sextet, JHH ¼ 7.3 Hz, 2H, CH2Me); 1.37 (quintet, JHH
¼
¼
ꢀ
60–70 for 1–4.5 h. The reaction course was monitored by
2
7.2 Hz, 2H, CH2Et); 1.73 (s, 1H, NH); 2.49 (dt, JHP
31 NMR spectroscopy. The resulting mixture was diluted
with 20 mL of water, and the target product was extracted
with CHCl3 (3 ꢁ 15 mL). The extract was washed with 30%
aq. R (3 ꢁ 10 mL), dried over anhydrous Na2SO4, and
evaporated under vacuum. The resulting residue was kept at
3
3
11.2 Hz, JHH ¼ 7.4 Hz, 2H, PCH2); 2.52 (t, JHH ¼ 7.0 Hz,
3
3
2H, CH2Pr); 2.92 (dt, JHP ¼ 11.3 Hz, JHH ¼ 7.4 Hz, 2H,
PCH2CH2); 7.40–7.53 (m, 6H, meta-CH þ para-CH); 7.72
3
3
4
(ddd, JHP ¼ 11.5 Hz, JHH ¼ 7.8 Hz, JHH ¼ 1.7 Hz, 4H,
ortho-CH). 13C NMR (75.50 MHz): d ¼ 14.1 (s, CH3); 20.5
3
ꢀ
50 (1 torr) for 1 h and dissolved in 5% aq. HCl (15 mL).
The solution obtained was washed with benzene
(3 ꢁ 10 mL), alkalized with a saturated aqueous solution of
(s, CH2Me); 30.5 (d, J ¼ 71.0 Hz, PCH2); 32.2 (s, CH2Et);
P
2
43.1 (d, J ¼ 2.1 Hz, PCH2CH2); 49.5 (s, CH2Pr); 128.8
P
(d, 3J
¼ 11.7 Hz, meta-CH); 130.8 (d, 2J
¼ 9.4 Hz,
P
P
K2CO3 until pH
¼
12, and extracted with CHCl3
4
ortho-CH); 131.9 (d, J ¼ 2.8 Hz, para-CH); 133.2 (d, J
P
P
(3 ꢁ 10 mL). The extract was dried over anhydrous Na2SO4
and evaporated under vacuum. The resulting residue was
recrystallized (amines 9–11) or purified by column chroma-
tography on silica gel using a CHCl3–CH3OH mixture
(20:2) as an eluent (amines 6–8, 12). The reaction condi-
tions in each particular case, yields and main characteristics
of amines 6–12 are summarized in Table 1.
¼ 98.8 Hz, ipso-C). 31P NMR (121.56 MHz): d ¼ 31.6. ESI-
MS: m/z (Irel, %): 302 (100) [M þ H]þ, 324 (33) [MþNa]þ,
340 (9) [M þ K]þ, 603 (18) [2MþH]þ, 625 (11) [2MþNa]þ.
2-Octylaminoethyldiphenylphosphine oxide (8)
2-Octylaminoethyldiphenylphosphine oxide (8) was synthesized
according to the general procedure using phosphine oxide 3,
14.8 g (19 mL, 114.6 mmol) octylamine, 50% aqueous solution
of KOH (1.6 g, 28.6 mmol) and DMSO (15 mL) (70 ꢀC, 3 h).
The resulting residue was purified by column chromatography
on silica gel (CHCl3–MeOH, 20:2) and recrystallized from ethyl
acetate. Yield: 5.0 g (74%); m.p.: 79.5–80.5 ꢀC. Literature m.p.
2-Methylaminoethyldiphenylphosphine oxide (6)
2-Methylaminoethyldiphenylphosphine oxide (6) was synthe-
sized according to the general procedure using 1.37 g
(5.3 mmol) of phosphine oxide 3, 4.3 mL 40% aqueous solu-
tion of methylamine (3.86 g, 124 mmol), 50% aqueous solu-
tion of KOH (1.1 g, 18.6 mmol) and DMSO (10 mL) (70 ꢀC,
1 h). The resulting residue was purified by column chroma-
tography on silica gel (CHCl3–MeOH, 20:2). Yield: 2.80 g
(79%); m.p.: 61–63 ꢀC. Literature m.p. 28–30 ꢀC.[24] 1H
NMR (300.28 MHz): d ¼ 1.68 (br s, 1H, NH); 2.36 (s, 3H,
3
35 ꢀC.[9] 1H NMR (300.28 MHz): d ¼ 0.86 (t, JHH ¼ 6.5 Hz,
3
3H, CH3); 1.17–1.35 (m, 10H, C5H10Me); 1.41 (quintet, JHH
2
3
¼ 6.7 Hz, 2H, CH2Hex); 2.52 (dt, JHP ¼ 11.2 Hz, JHH
¼
3
7.3 Hz, 2H, PCH2); 2.55 (t, JHH ¼ 7.1 Hz, 2H, CH2Hept); 2.95
3
3
(dt, JHP ¼ 11.0 Hz, JHH ¼ 7.3 Hz, 2H, PCH2CH2); 7.41–7.55
2
3
3
CH3); 2.48 (dt, JHP ¼ 11.3 Hz, JHH ¼ 7.4, 2H, PCH2); 2.89 (m, 6H, meta-CH þ para-CH); 7.73 (ddd, JHP ¼ 11.5 Hz,
3
3
4
(dt, JHP ¼ 11.4 Hz, JHH ¼ 7.4 Hz, 2H, PCH2CH2); 3JHH ¼ 7.9 Hz, JHH ¼ 1.7 Hz, 4H, ortho-CH). 13C NMR
3
7.41–7.54 (m, 6H, meta-CH þ para-CH); 7.72 (ddd, JHP
¼
(75.50 MHz): d ¼ 14.1 (s, CH3); 22.6 (s, CH2Me); 27.3 (s,
3
4
11.5 Hz, JHH ¼ 7.9 Hz, JHH ¼ 1.6 Hz, 4H, ortho-CH). 13C
CH2Pent); 29.2 (s, CH2Pr); 29.5 (s, CH2Bu); 30.0 (s, CH2Hex);
2
NMR (75.50 MHz): d ¼ 30.3 (d, J ¼ 71.1 Hz, PCH2); 36.4
P
30.4 (d, J ¼ 71.0 Hz, PCH2); 31.8 (s, CH2Et); 42.9 (d, J
P
1.4 Hz, PCH2CH2); 49.8 (s, CH2Hept); 128.7 (d, 3J
¼
P
2
3
(s, CH3); 45.1 (d, J ¼ 2.0 Hz, PCH2CH2); 128.9 (d, J
¼
P
P
P
2
2
¼ 11.6 Hz, meta-CH); 130.9 (d, J ¼ 9.4 Hz, ortho-CH);
11.7 Hz, meta-CH); 130.7 (d, J ¼ 9.4 Hz, ortho-CH); 131.8
P
P
4
4
132.0 (d, J ¼ 2.7 Hz, para-CH); 133.1 (d, J ¼ 98.6 Hz,
(d, J ¼ 2.7 Hz, para-CH); 133.0 (d, J ¼ 98.7 Hz, ipso-C).
P
P
P
P
ipso-C). 31P NMR (121.56 MHz): d ¼ 31.4. ESI-MS: m/z (Irel,
%): 260 (100) [M þ H]þ, 282 (12) [MþNa]þ, 519 (94)
[2MþH]þ, 541 (80) [2MþNa]þ. Anal. Calcd. for
31P NMR (121.56 MHz): d ¼ 31.2. ESI-MS: m/z (Irel, %): 358
(99) [Mþ H]þ, 380 (40) [MþNa]þ, 715 (12) [2MþH]þ, 737
(13) [2MþNa]þ. Anal. Calcd. for C22H32NOP: C, 73.92; H,
9.02; N, 3.92; P, 8.66. Found: C, 73.99; H, 8.99; N, 4.01;
P, 8.47%.
3To remove the DMSO residues into a trap cooled with liquid nitrogen.