1324
M. S. Rahman et al.
PAPER
1H NMR (400 MHz; CDCl3): d = 0.80 (t, 3H, J = 7 Hz, CH3), 1.22
(m, 2H, CH3CH2), 1.52 (m, 2H, CH3CH2CH2), 2.83 (m, 6H, CH2P
and CH2N), 3.17 (m, 4H, CH2CH2P), 7.40-7.75 (m, 20H, Ph).
31P NMR (145.7 MHz; CDCl3): d = +30.5.
13C NMR (90.5 MHz; CDCl3): d = 11.2 (s, CH3), 19.5 (s, CH3CH2),
24.1 (d, 1JPC = 15 Hz, CH2P), 45.2 (d, 2JPC = 27 Hz, CH2CH2P), 49.2
(s, CH2N), 128.7 (d, 3JPC = 7 Hz, Cmeta), 129.3 (s, Cpara), 132.7 (d,
2JPC = 19 Hz, Cortho), 136.0 (d, 1JPC = 11 Hz, Cipso).
HRMS: calcd for C17H22NP (M++1) 272.1568. Found: 272.1585.
13C NMR (90.5 MHz; CDCl3): d = 13.4 (s, CH3), 19.9 (s, CH3CH2),
1
24.8 (d, JPC = 70 Hz, CH2P), 24.6 (s, CH3CH2CH2), 47.2 (s,
CH2CH2P), 52.5 (s, CH2N), 129.2 (d, 3JPC = 12 Hz, Cmeta), 130.8 (d,
[2-(Diphenylphosphino)ethyl]-iso-propylamine∑HCl Salt (3b)
Yield: 84%; mp: 170 ∞C.
2JPC = 10 Hz, Cortho), 131.4 (s, Cpara), 132.0 (d, 1JPC = 112 Hz, Cipso).
1H NMR (360 MHz; CDCl3): d = 1.25 (d, 6H, J = 6.5 Hz, CHMe2),
2.72 (m, 2H, CH2P), 2.92 (br m, 2H, CH2CH2P), 3.13 (septet, 1H,
J = 6.5 Hz, CHMe2), 7.23-7.44 (m, 10H, Ph), 9.61 (br s, 2H, NH2).
HRMS: calcd for C32H37NO2P2 (M++1) 530.2378. Found:
530.2363.
Bis-[2-(diphenylphosphineoxide)ethyl]-n-heptylamine (2c)
Mp: 149-150 ∞C.
IR (KBr disc): n = 1178 (P=O) cm-1.
1H NMR (400 MHz; CDCl3): d = 0.79 (t, 3H, J = 7 Hz, CH3), 1.06-
1.80 (m, 10H, CH3CH2CH2CH2CH2CH2), 2.22-2.28 (m, 6H, CH2N
and CH2P), 2.71 (m, 4H, CH2CH2P), 7.35-7.64 (m, 20H, Ph).
31P NMR (145.7 MHz; CDCl3): d = -18.8.
13C NMR (90.5 MHz; CDCl3): d = 19.1 (s, CH3), 24.3 (d, 1JPC = 15
Hz, CH2P), 42.3 (d, 2JPC = 27 Hz, CH2CH2P), 50.1 (CHMe2), 128.8
3
2
(d, JPC = 7 Hz, Cmeta), 129.2 (s, Cpara), 132.8 (d, JPC = 19 Hz,
Cortho), 136.2 (d, 1JPC = 12 Hz, Cipso).
IR (KBr disc): n = 3436 (N-H) cm-1.
31P NMR (145.7 MHz; CDCl3): d = +31.9.
Anal. calcd for C17H23ClNP: C, 66.35; H, 7.5; N, 4.55: Found: C,
66.25; H, 7.55; N, 4.50.
13C NMR (90.5 MHz; CDCl3): d = 14.1 (s, CH3), 22.6, 26.3, 26.9,
27.0, 27.3, 29.2, 29.7, 31.8 (s, aliphatic CH2’s), 45.4 (s, CH2CH2P),
53.3 (s, CH2N), 128.7 (d, 3JPC = 11.5 Hz, Cmeta), 130.7 (d, 2JPC = 9.5
Hz, Cortho), 131.8 (s, Cpara), 133.8 (d, 1JPC = 99 Hz, Cipso).
HRMS: calcd for C35H43NO2P2 (M++1) 572.2847. Found:
572.2863.
[2-(Diphenylphosphino)ethyl]-n-butylamine∑HCl Salt (3c)
Yield: 88%; mp: 124-125 ∞C.
IR (KBr disc) n = 3415 (N-H) cm-1.
1H NMR (360 MHz; CDCl3): d = 0.79 (t, 3H, J = 7 Hz, CH3), 1.25
(sextet, 2H, J = 7 Hz, CH3CH2), 1.71 (m, 2H, CH3CH2CH2), 2.64
(m, 2H, CH2P), 2.80 (t, 2H, J = 8 Hz, CH2N), 2.94 (m, 2H,
CH2CH2P), 7.28-7.40 (m, 10H, Ph), 9.50 (br d, 2H, NH2).
Bis-[2-(diphenylphosphineoxide)ethyl]benzylamine (2d)
Mp: 169-170 ∞C.
IR (KBr disc): n = 1178 (P=O) cm-1.
1H NMR (360 MHz; CDCl3): d = 2.31 (m, 4H, CH2P), 2.78 (m, 4H,
CH2CH2P), 3.49 (s, 2H, PhCH2), 7.04-7.64 (m, 25H, Ph).
31P NMR (145.7 MHz; CDCl3): d = -20.2.
13C NMR (90.5 M Hz; CDCl3): d = 13.4 (s, CH3), 19.9 (s, CH3CH2),
1
24.1 (d, JPC = 14 Hz, CH2P), 27.7 (s, CH3CH2CH2), 44.9 (d,
2JPC = 26.5 Hz, CH2CH2P), 47.2 (s, CH2N), 128.7 (d, JPC = 7 Hz,
3
31P NMR (145.7 MHz; CDCl3): d = +31.7.
2
Cmeta), 129.3 (s, Cpara), 132.7 (d, JPC = 19 Hz, Cortho), 136.0 (d,
13C NMR (90.5 MHz; CDCl3): d = 26.9 (d, 1JPC = 69.4 Hz, CH2P),
1JPC = 11 Hz, Cipso).
2
45.6 (d, JPC = 22.4 Hz, CH2CH2P), 58.0 (s, PhCH2), 127.1-138.3
IR (KBr disc): n = 3415 (N-H) cm-1.
HRMS: calcd for C18H24NP (M++1) 286.1725. Found: 286.1728.
(Carom).
HRMS: calcd for C35H35NO2P2 (M++1) 564.2221. Found:
564.2219.
[2-(Diphenylphosphino)ethyl]-sec-butylamine∑HCl Salt (3d)
Yield: 92%; mp: 138-139 ∞C.
IR (KBr disc): n = 3412 (N-H) cm-1.
Reduction of Aminophosphines Oxides 1 to 3; General Proce-
dure
The appropriate aminophosphine oxide (0.5g) was suspended in tol-
uene (25 mL). Et3N (6 mL) was added and the mixture was stirred
whilst cooled to 0 ∞C. Trichlorosilane (5 equiv) was then added
dropwise and the mixture was then refluxed for 3.5 h. After cooling
to r.t., the reaction mixture was diluted with Et2O (100 mL), and a
few drops of sat. Na2CO3 were added to destroy excess reducing
agent. The mixture was filtered under Ar and concentrated to leave
a yellow oil. The residue was dissolved in Et2O (25 mL) and contin-
uously purged with Ar whilst concd HCl was added dropwise until
the formation of a white precipitate. In some cases, a small amount
of H2O (approx 2 mL) was added to encourage precipitation. The
HCl salt was subsequently filtered off and dried under vacuum.
1H NMR (360 MHz; CDCl3): d = 0.79 (t, 3H, J = 7 Hz, CH3CH2),
1.21 (d, 3H, J = 6.5 Hz, CH3CH), 1.52 (m, 1H, CH3CH2), 1.84 (m,
1H, CH3CH2), 2.77 (m, 2H, CH2P), 2.80-2.90 (m, 3H, CHN and
CH2CH2P), 7.23-7.51 (m, 10H, Ph), 9.58 (br. d, 2H, NH2).
31P NMR (145.7 MHz; CDCl3): d = -19.3.
13C NMR (90.5 MHz; CDCl3): d = 9.9 (s, CH3), 15.4 (s, CH3), 23.9
1
2
(d, JPC = 12 Hz, CH2P), 25.8 (s, CH3CH2), 41.9 (d, JPC = 26 Hz,
3
CH2CH2P), 55.4 (s, CHN), 128.9 (d, JPC = 7 Hz, Cmeta), 129.4 (s,
C
para), 132.0 (d, 2JPC = 19 Hz, Cortho), 135.3 (d, 1JPC = 11 Hz, Cipso).
HRMS: calcd for C18H24NP (M++1) 286.1725. Found: 286.1728.
[2-(Diphenylphosphino)ethyl]-tert-butylamine∑HCl Salt (3e)3
Yield: 82%; mp: 208-209 ∞C.
IR (KBr disc): n = 3412 (N-H) cm-1.
1H NMR (360 MHz; CDCl3): d = 1.28 (s, 9H, CMe3), 3.04 (m, 2H,
CH2CH2P), 3.15 (m, 2H, CH2P), 7.35-7.63 (m, 10H, Ph).
[2-(Diphenylphosphino)ethyl]-n-propylamine∑HCl Salt (3a)
Yield: 89%; mp: 137-139 ∞C.
IR (KBr disc): n = 3411 (N-H) cm-1.
1H NMR (360 MHz; CDCl3): d = 0.80 (t, 3H, J = 7.4 Hz, CH3), 1.74
(m, 2H, CH3CH2), 2.65-2.79 (m, 4H, CH2N and CH2P), 2.93 (br. m,
2H, CH2CH2P), 7.28-7.42 (m, 10H, Ph), 9.70 (br. s, 2H, NH2).
31P NMR (145.7 MHz; CDCl3): d = -20.1.
31P NMR (145.7 MHz; CDCl3): d = -19.9.
13C NMR (90.5 MHz; CDCl3): d = 25.0 (d, JPC = 14 Hz, CH2P),
1
2
26.0 (s, CMe3), 39.4 (d, JPC = 28 Hz, CH2CH2P), 56.9 (s, CMe3),
Synthesis 2000, No. 9, 1320–1326 ISSN 0039-7881 © Thieme Stuttgart · New York