Synthesis, Stability, and Sorption Properties of 1-Hydroxy-1,1-bis(H-Phosphinates) 197
3
108 Hz); 126.5 (arom., s), 128.6 (arom., s), 129.3
δ1.34 (CH , t, 3H, JHP = 8 Hz); 6.87 (PH, d, 2H,
3
(arom., s), 138.4 (arom., d, JCP = 14 Hz); 31P δ31.1 (d,
1 JHP = 525 Hz); 13C{ H} δ16.8 (CH3, s); 73.7
1
1 JPH = 510 Hz). ESI-MS: m/z 184.5 [M – H+]−. TLC
(PCP, t, JPC = 89 Hz); 31Pδ25.7 (m). ESI-MS: m/z
1
172.5 [M – H+]−; 384.4 [2M + K+– 2H+]−; 558.6
[3M + K+– 2H+]−; 732.7 [4M + K+– 2H+]−. TLC
(MeCN:MeOH:NH4OH 10:5:1): R = 0.6.
f
1-Hydroxy-ethyl-(H-phosphinic Acid). Reaction
time: 50 days. Purification: mobile phase
(MeCN:MeOH:NH4OH 3:1:2): R = 0.3.
f
MeCN:MeOH:NH4OH 3:1:2;
R
=
0.8. Yield:
1-Hydroxy-ethyl-1,1-bis(H-phosphinic Acid) (Et-
f
65% of colorless oil. NMR (DMSO-d6): 1H δ1.18
Pin2). Yield: 45% as (NH4)2EtPin2·1/2H2O. Anal.
1
(CH , m, 3H); 3.67 (CH, m, 1H); 6.67 (PH, d, 1H,
Calcd. for C2H9O5P2·(NH3)2· /2H2O: C, 15.6; H, 7.4;
3
1 JHP = 520 Hz); 13C{ H} δ15.8 (CH3, d, 2 JCP = 3 Hz);
1
N, 12.1; P, 26.7. Found: C, 15.4; H, 7.3; N, 11.9;
64.4 (CH, d, JCP = 113 Hz); 31P δ34.3 (dq, JPH
=
1
1
1
3
P, 26.7. NMR (D2O): H δ1.07 (CH , td, 3H, JHH
=
3
520 Hz; 3 JPH = 17 Hz). ESI-MS: m/z 108.7 [M – H+]−.
4
8 Hz, JHP = 1 Hz); (CH , m, 2H); 7.02 (PH, dt, 2H,
2
1 JHP = 549 Hz, JHH = 15 Hz); 13C{ H} δ8,1 (CH3,
4
1
TLC (MeCN:MeOH:NH4OH 10:5:1): R = 0.4.
f
3
1
t, JCP = 7 Hz); 24.0 (CH2, s); 74.2 (PCP, t, JPC
=
1
95 Hz); 31P δ26.6 (d, JPH = 550 Hz). ESI-MS: m/z
186.5 [M – H+]−; 386.5 [2M + Na+– 2H+]−. TLC
1-Hydroxy-propyl-(H-phosphinic Acid).
Reaction time: 25 days. Purification: mobile
phase MeCN:MeOH:NH4OH 3:1:2; R = 0.8. Yield:
(MeCN:MeOH:NH4OH 3:1:2): R = 0.3.
f
f
57% of yellowish oil. NMR (DMSO-d6): 1H δ0.84
3
(CH , t, 3H, JHH = 7 Hz); 1.51 (CH , m, 2H); 3.53
3
2
1-Hydroxy-(H-Phosphinates)—General Method
(CH, m, 1H); 13C{ H} δ10.1 (CH3, d, JCP = 13 Hz);
1
3
2
1
22.9 (CH2, d, JCP = 4 Hz); 70.8 (CH, d, JCP = 111
Hz); 31P δ34.3 (d, 1 JPH = 541 Hz). ESI-MS: m/z 122.7
1-Hydroxy-1,1-bis(H-phosphinate) (2.5 mmol) was
dissolved in 6 M hydrochloric acid (15 mL) and
heated at 80◦C for 4–50 days (for more details,
see below). Then, the solution was evaporated un-
der reduced pressure and the product was puri-
fied by column chromatography (SiO2, for the mo-
[M – H+]−. TLC (MeCN:MeOH:NH4OH 10:5:1): R =
f
0.5.
Kinetics of Hydrolysis
bile phase and R , see below). Resulting ammonium
f
salts were purified on a strong cation exchange resin
(Dowex 50, elution with water). The resulting prod-
uct was isolated in the form of free acid by freeze–
drying (aromatic derivatives) or rotary evaporation
(aliphatic derivatives).
The hydrolysis of the bis(phosphinates) was fol-
lowed by 31P NMR at the compound concentra-
tion of 10 mM. The experiments were performed at
constant temperature (80◦C) maintained by a ther-
mostated bath. The experiments were carried in
buffered solutions (concentration 1 mol dm−3; HCl,
pH 0; ClCH2COOH/NaOH, pH 2.7; Tris/HCl, pH 8.5;
ethanolamine/HCl, pH 9.8; NaOH, pH 14).
1-Hydroxy-1-phenyl-methyl-(H-phosphinic Acid).
Reaction time: 4 days. Purification: mobile phase
MeCN:MeOH:NH4OH 3:1:2; R = 0.8. Yield: 59% of
f
white powder. Anal. Calcd. for C7H9P1O3: C, 48.8;
X-Ray Diffraction
1
H, 5.3. Found: C, 48.5; H, 5.1. NMR (DMSO-d6): H
2
δ4.75 (CHP, d, 1H, JHP = 9 Hz); 6.85 (PH, d, 1H,
Single crystals of H2PhPin2·2H2O and H2BnPin2
were obtained by diffusion of dichloromethane va-
por into the tetrahydrofurane solution. The diffrac-
tion data were collected at 150 K (Cryostream
Cooler, Oxford Cryosystem) using a Nonius Kappa
CCD diffractometer and Mo Kα radiation (λ =
1
1 JHP = 518 Hz); 7.43 (arom., m, 5H); 13C{ H} δ71.7
1
(CHP, d, JCP = 105 Hz); 127.0, (arom., d, JCP
=
5 Hz), 130.1 (arom., d, JCP = 3 Hz), 130.7 (arom.,
d, JCP = 2 Hz), 137.6 (arom., s); 31P δ28.8 (dd, 1 JPH
=
518 Hz, 2 JPH = 9 Hz). ESI-MS: m/z 170.5 [M – H+]−.
˚
TLC (MeCN:MeOH:NH4OH 10:5:1): R = 0.6.
0.71073 A) and analyzed using the HKL DENZO
f
program package [16]. The structures were solved
by using direct methods (SIR92) [17] and re-
fined by using a full-matrix least-squares technique
(SHELXL97) [18]. All non-hydrogen atoms were re-
fined anisotropically. All hydrogen atoms were lo-
cated in the difference map of electron density; how-
ever, they were placed in theoretical (C H) or origi-
nal (O H) positions with thermal parameters Ueq(H)
= 1.2 Ueq(X) as their free refinement led to some
1-Hydroxy-2-phenyl-ethyl-(H-phosphinic Acid).
Reaction time: 15 days. Purification: mobile phase
MeCN:MeOH:NH4OH 3:1:2; Rf = 0.4. Yield: 72% of
white powder. Anal. Calcd. for C8H11P1O3: C, 51.6;
1
H, 6.0. Found: C, 51.7; H, 5.8. NMR (DMSO-d6): H
δ2.94 (CH , m, 2H); 3.82 (CHP, m, 1H); 6.85 (PH,
2
d, 1H, JHP = 510 Hz); 7.36 (arom., m, 5H); 13C{ H}
1
1
2
1
δ38.2 (CH2, d, JCP = 5 Hz) 74.4 (CHP, d, JCP
=
Heteroatom Chemistry DOI 10.1002/hc