A new direction in the reaction of α-iminocarboxylate salts with dialkyl chlorophosphites: Formation of bis[1-(dialkoxyphosphoryl)alkyl]amines

Article abstract of DOI:10.1070/MC2005v015n01ABEH001991

Sodium benzylidene-L-phenylglycinate and sodium benzylidene-D-alaninate react with dialkyl chlorophosphites and water contained in their crystal lattices to give stereoisomeric bis[1-(dialkoxyphosphoryl)alkyl]amines.

Full text of DOI:10.1070/MC2005v015n01ABEH001991

,
2005, 15(1), 40–42
A new direction in the reaction of α-iminocarboxylate salts with dialkyl
chlorophosphites: formation of bis[1-(dialkoxyphosphoryl)alkyl]amines
Mudaris N. Dimukhametov,* Rashid Z. Musin, Boris I. Buzykin, Shamil K. Latypov and Vladimir F. Mironov
A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Centre of the Russian Academy of Sciences,
4
20088 Kazan, Russian Federation. Fax: +7 8432 755 322; e-mail: mudaris@iopc.knc.ru
DOI: 10.1070/MC2005v015n01ABEH001991
Sodium benzylidene-L-phenylglycinate and sodium benzylidene-D-alaninate react with dialkyl chlorophosphites and water con-
tained in their crystal lattices to give stereoisomeric bis[1-(dialkoxyphosphoryl)alkyl]amines.
The addition of dialkyl phosphites or their salts to imines is a
phosphites as an example. The reaction resulted in 1,4-bis-
[1-(dialkoxyphosphoryl)benzyl]-2,5-diketopiperazines. In this
2
common method for the synthesis of α-aminophosphonates
(
including stereoselective synthesis). This phosphorylation of
connection, it is of considerable interest to study the stereo-
chemistry of the chiral carbon atom with a P–C bond formed
in the reaction and to use this reaction as an approach to the
synthesis of chiral α-aminophosphonates, precursors of enantio-
merically pure α-aminophosphonic acids. This possibility was
imines derived from α-amino acids (α-imino acids) occurs only
with tert-butyl R-(–)-phenylglycinate derivatives.1 Recently,
α-imino acids were phosphorylated through the carboxylate
function using sodium benzylideneglycinate and monochloro-
4
0
Mendeleev Commun. 2005

,
2005, 15(1), 40–42
previously shown in the reaction of chiral β-iminoalcohols with
dialkyl chlorophosphites.3
Compounds 9a,b incorporating two chiral carbon atoms in
the same chemical environment are formed as mixtures of
d,l (RR+SS) and meso (RS+SR) forms. The diastereomers in
,4
We obtained sodium benzylidene-L-phenylglycinate 1a and
sodium benzylidene-D-alaninate 1b from L-(+)-phenylglycine
1
which the proton of the PCH fragment in the H NMR spectrum
†
and D-(+)-alanine, respectively, in order to use them as the
displays a signal in a lower field and with smaller absolute
magnitudes of 2JHP show zero optical rotation ([a]D = 0°)
(meso forms). On the other hand, the diastereomers with an
upfield proton of the same fragment and with higher magni-
20
derivatives of chiral α-iminocarboxylic acids.
Imines 1a,b were unexpectedly found to react quantitatively
with dialkyl chlorophosphites in a 1:2 ratio to give stereo-
isomeric bis[1-(dialkoxyphosphoryl)alkyl]amines 9a–c as the
final products (Scheme 1).‡ Compounds 9a–c were purified
by column chromatography; the analytically pure samples of
individual diastereomers were isolated from corresponding eluted
fractions. The structures of compounds 9a–c were proved by
2
20
D
tudes of J show considerable optical rotation angles [a] .
HP
This allows us to assign them a d,l-structure with the predomi-
nance of one of the enantiomers. The d,l:meso ratios for the
raw reaction mixtures are 2.4:1 (9a) and 2.1:1 (9b). The two
1
13
31
Elemental analysis of a mixture of 9a (d,l) and 9a (meso), 1:1. Found
NMR spectroscopy ( H, C, P), mass spectrometry, IR spectro-
scopy and polarimetry; the compositions were confirmed by
(
%): C, 56.88; H, 6.82; N, 3.00; P, 12.74. Calc. for C H NO P (%):
22 33 6 2
C, 56.29; H, 7.04; N, 2.98; P, 13.22.
§
elemental analysis.
2
0
20
1
9
b (d,l): n 1.5120, [a]D –12.0° (c 2.9, C H ). H NMR (400 MHz,
D
6
6
3
CDCl ) d: 1.00, 1.19, 1.26, 1.27 (4d, 24H, 8Me, JHH 6.2 Hz), 2.45
3
†
2
Sodium benzylidene-L-phenylglycinate 1a. L-(+)-Phenylglycine (1.89 g,
(br. s, 1H, NH), 3.64 (d, 2H, 2HCP, J 22.0 Hz), 4.41, 4.64 (2m, 4H,
4HCO), 7.27, 7.35–7.36 (2m, 10H, 2Ph). C-{ H} NMR (100.6 MHz,
HP
1
3
1
1
3 mmol) was added to a solution of sodium hydroxide (0.52 g, 13 mmol)
in 15 ml of anhydrous MeOH. Once the acid had dissolved completely
20 °C), benzaldehyde (1.5 g, 14 mmol) was added with stirring. The
3
CD CN) d: 23.88, 23.90, 24.33, 24.35 (4d, 4Me, JCP 2.4, 2.7, 2.4,
3
3
1
(
2.7 Hz), 24.45, 24.47 (2d, 4Me, J 0.8–1.0 Hz), 58.68 (dd, CHP, J
156.0 Hz, JCP 17.4 Hz), 72.29, 72.33, 72.42, 72.46 (4d, 4CHO, JCP
3.7, 3.6, 3.6, 3.5 Hz), 129.10 (s, CPh), 129.37 (s, C ), 130.23 (s, C ),
136.10 (s, C ). P NMR (CD CN) d: 21.6 (s). IR (thin layer, n/cm ):
CP CP
3
2
suspension formed in the reaction mixture for a day was filtered off; the
solvent was removed from the filtrate by evaporation in vacuo. The
residue was recrystallised from ethanol. Compound 1a (2.8 g, yield
p
m
Ph
o
Ph
–1
i
Ph
31
3
8
2%) was obtained as a white powder, mp 235–238 °C (decomp.),
990 (P–O–C), 1246 (P=O), 3325 (NH). MS (CI), m/z (%): 526 (100)
20
1
+
[
5
a] +32.5° (c 0.88, MeOH). H NMR (400 MHz, CD OD, TMS), d:
.04 [s, 1H, HCC(O)], 7.14–7.95 (m, 10H, 2Ph), 8.36 (s, 1H, HC=N).
[M + H] .
D
3
9b (meso): n 1.5165, [a] D2 0 0° (c 2.5, C H ). 1H NMR (400 MHz,
2
0
D
6
6
–1
3
IR (Vaseline oil, n/cm ): 1608 (C=N), 1646 (C=O). Found (%): C,
6
N, 5.36.
CD CN) d: 1.04, 1.22, 1.25, 1.26 (4d, 24H, 8Me, J 6.1–6.2 Hz), 4.16
3
HH
2
9.43; H, 5.03; N, 5.38. Calc. for C H NO Na (%): C, 68.96; H, 4.60;
(d, 2H, 2HCP,
J 17.2 Hz), 4.47, 4.60 (2m, 4H, 4CHO), 7.27 (m,
15
12
2
HP
1
1
3
10H, 2Ph). C-{ H} NMR (100.6 MHz, CD CN) d: 23.98, 24.23,
24.29, 24.42 (4d, 8Me, J 5.5, 3.4, 3.3, 5.0 Hz), 60.53 (dd, CHP, J
CP CP
151.9 Hz,
128.74 (d, CPh, JCP 2.8 Hz), 129.10 (br. s, CPh), 129.90 (d, C , J
CP
6.1 Hz), 137.81 (d, C , J 3.4 Hz). P NMR (CD CN) d: 22.1 (s).
IR (thin layer, n/cm ): 991 (P–O–C), 1243 (P=O), 3345 (NH).
Elemental analysis of a mixture of 9b (d,l) and 9b (meso), 1:1. Found
(%): C, 56.88; H, 6.82; N, 3.00; P, 12.74. Calc. for C H NO P (%):
3
3
1
Sodium benzylidene-D-alanilate 1b was obtained similarly to com-
i
3
2
pound 1a (recrystallisation from Pr OH). Yield 75%, mp 203–206 °C
J
10.4 Hz), 72.17, 72.52 (2d, 4CHO, JCP 7.5, 7.3 Hz),
CP
2
0
1
p
5
m
o
Ph
3
(
decomp.), [a] –13.6° (c 1.45, MeOH). H NMR (400 MHz, CD OD,
D
3
3
3
i
2
31
TMS), d: 1.47 (d, 3H, Me, J 7 Hz), 3.99 [q, 1H, CHC(O), J 7 Hz],
HH
HH
Ph CP 3
–
1
–1
7
1
.40–7.80 (m, 5H, Ph), 8.31 (s, 1H, HC=N). IR (Vaseline oil, n/cm ):
596 (C=N), 1642 (C=O). Found (%): C, 60.63; H, 4.83; N, 7.39. Calc.
for C H NO Na (%): C, 60.30; H, 5.02; N, 7.04.
1
0
10
2
26 41
6 2
‡
Bis[1-(diethoxyphosphoryl)benzyl]amine 9a. Diethyl chlorophosphite
C, 59.43; H, 7.81; N, 2.67; P, 11.81.
20
20
1
(
1.2 g, 7.7 mmol) in CHCl3 (5 ml) was added with stirring at room
9c (diastereomer d ): n 1.4880, [a]D +6.80° (c 1.4, C H ). H NMR
1 D 6 6
3
temperature under dry argon to a suspension of compound 1a (1 g,
[600 MHz, (CD ) CO)] d: 1.11, 1.27 (2t, 6H, 2MeCOP , J 7.1 Hz),
3 2 1 HH
3
3
3
.8 mmol) in 10 ml of anhydrous CHCl . After a day, the precipitate
1.22 (dd, 3H, MeCP , J 6.9 Hz, J 17.5 Hz), 1.27, 1.28 (2t, 6H,
3
2 HH HP
2MeCOP , JHH 7.1 Hz), 2.83 (ddq, 1H, HCP2, JHP 15.2 Hz, JHH
7.0 Hz, J 0.5 Hz), 2.87 (br. s, 1H, NH), 3.37, 3.82 (2m, 2H, H COP ),
3
2
3
was filtered off; the solvent was removed from the filtrate by evapora-
tion in vacuo. Compound 10 (0.5 g) was isolated from the residue by
treatment with diethyl ether. The solvent was removed from the ethereal
layer by evaporation in vacuo, and the residue was chromatographed on
Chemapol silica gel (L 100/160 mesh) in the toluene–ethyl acetate
system (1:2). The composition of the eluate fractions was monitored by
TLC on Silufol UV 254 plates using iodine vapour to visualise the
chromatograms. The following compounds were isolated in sequence:
2
4
HP
2
1
2
4.08–4.10 (m, 6H, H COP + 2H COP ), 4.34 (d, 1H, HCP , JHP
2
1
2
2
1
1
3
1
20.3 Hz), 7.32–7.49 (m, 5H, Ph). C-{ H} NMR (100.6 MHz, CDCl )
3
2
3
d: 13.76 (d, MeCP , J 1.5 Hz), 16.30 (d, MeCOP , J 5.8 Hz), 16.44
2
CP
2
CP
3
3
(d, C'H COP , J 5.7 Hz), 16.48 (d, MeCOP , J 5.6 Hz), 16.51 (d,
C'H COP , J 5.8 Hz), 47.28 (dd, CHP , J 159.2 Hz, J 15.3 Hz),
57.90 (dd, CHP , JCP 153.8 Hz, JCP 15.6 Hz), 62.30 (d, CH OP ,
3
2
CP
1
CP
3
1
3
3
1
CP
2
CP
CP
1
3
1
2
1
2
2
8
a (0.1 g) obtained as a yellowish liquid; 0.09 g of compound 3 (R = Et);
JCP 6.7 Hz), 62.45 (d, C'H OP , JCP 7.0 Hz), 63.00 (d, CH OP ,
2
1
2
2
2J 6.9 Hz), 63.05 (d, C'H OP , 2JCP 7.0 Hz), 128.12 (d, CPh, JCP
p
5
9a (meso) and 9b (d,l) obtained as colourless oily liquids. The overall
CP
2
2
m
Ph
4
o
Ph
3
yield of compound 9a was 1.1 g (61%).
3.1 Hz), 128.52 (d, C
,
JCP 2.4 Hz), 128.85 (d, C , J 6.1 Hz),
CP
i
2
31
4
Compounds 9b,c were obtained (similarly to compound 9a) as colour-
less oils. Compounds 9b and 9c were chromatographed using benzene–
acetonitrile (2:1) and toluene–acetonitrile (2:1) as the eluents, respec-
tively. The overall yields are: 55% for 9b and 67% for 9c.
135.03 (d, C , J 4.6 Hz). P NMR (CDCl ) d: 23.4 (d, P , JPP
Ph CP 3 1
4
–1
6 Hz), 28.0 (d, P2, JPP 6 Hz). IR (thin layer, n/cm ): 1025, 1050
+
(P–O–C), 1240 (P=O), 3325 (NH). MS (CI), m/z (%): 408 (100) [M + H] .
+
MS (EI, 70 eV), m/z (%): 270 (70.0) [M – P(O)(OEt) ] , 242 (38.0)
2
§
20
20
1
+
+
9
a (d,l): nD 1.5118, [a]D +24.5° (c 0.5, AcOEt). H NMR (600 MHz,
[M – P(O)(OEt) – C H ] , 133 (52.0) [M – P(O)(OEt) – P(O)(OEt) ] ,
2 2 4 2 2
3
+
CD CN) d: 1.10, 1.26 (2t, 12H, 4Me, J 7.1 Hz), 3.76 (d, 2H, 2HCP,
132 (100) [M – P(O)(OEt) – P(O)(OEt) – H] .
2 2
3
HH
2
20
20
JHP 21.7 Hz), 3.81, 3.91 (2m, 4H, 2CH ), 4.03–4.06 (m, 4H, 2CH ),
9c (diastereomer d ): n 1.4975, [a]D +16.60° (c 3.5, C H ).
2
2
2
D
6
6
.28–7.38 (m, 10H, 2Ph). 13C-{ H} NMR (150.9 MHz, CD CN) d:
1
1
H NMR (400 MHz, CDCl ) d: 1.10, 1.34 (2t, 6H, 2MeCOP , JHH
3 1
3
7
1
3
3
3
3
6.52, 16.54, 16.71, 16.73 (4d, 4Me, J 3.0, 3.1, 3.0, 2.5 Hz), 58.25
7.1 Hz), 1.22 (dd, 3H, MeCP , JHH 7.2 Hz, J 17.1 Hz), 1.28, 1.29
CP
2 HP
(2t, 6H, 2MeCOP , JHH 7.1 Hz), 2.81 (dq, 1H, HCP2, JHP 7.2 Hz,
1
3
3
2
(
dd, CHP, J 154.1 Hz, J 17.6 Hz), 63.73, 63.75, 63.84, 63.86 (4d,
CP
CP
2
2
p
Ph
5
3
4
CH , J 3.6, 4.0, 3.5, 3.5 Hz), 129.16, 129.17 (2d, C , J 1.5 Hz),
29.45, 129.46 (2d, C , J 1.0 Hz), 129.83, 129.85 (2d, C
JHH 7.2 Hz), 3.10 (br. s, 1H, NH), 3.75, 3.92 (2m, 2H, H COP ),
2
CP
CP
2
1
m
Ph
4
o
Ph
1
,
4.08–4.11 (m, 4H, 2H COP ), 4.17 (m, 2H, H COP ), 4.62 (dd, 1H,
CP
2 2 2 1
HCP , J 20.6 Hz, J 2.0 Hz), 7.28–7.44 (m, 5H, Ph). C-{ H} NMR
1 HP PP
3
i
2
31
2
4
13
1
JCP 3.0 Hz), 135.56, 135.57 (2d, CPh, JCP 2.0, 2.5 Hz). P NMR
–1
3
(
(
(
36.5 MHz, CD CN) d: 21.9 (s). IR (thin layer, n/cm ): 1025, 1052
P–O–C), 1216, 1249 (P=O), 3328 (NH). MS (EI, 70 eV), m/z (%): 332
92.0) [M – P(O)(OEt) ] , 242 (53.0) [M – P(O)(OEt) – 2(OEt)] .
(100.6 MHz, CDCl ) d: 16.25 (d, MeCOP , JCP 5.8 Hz), 16.44 (d,
3
3
1
3
3
C'H COP , JCP 6.0 Hz), 16.63 (d, MeCOP2, JCP 5.6 Hz), 16.69 (d,
3 1
+
+
C'H COP , 3J 5.5 Hz), 17.05 (br. s, MeCP ), 47.81 (dd, CHP , JCP
1
2
2
3 2 CP 2 2
2
0
20
1
3
1
3
9
a (meso): n 1.5180, [a]D 0° (c 1.2, AcOEt). H NMR (400 MHz,
155.7 Hz, J 7.2 Hz), 59.26 (dd, CHP , J 152.6 Hz, J 2.7 Hz),
CP 1 CP CP
D
3
2
2
CD CN) d: 1.14, 1.25 (2t, 12H, 4Me, J 7.1 Hz), 3.88–3.95 (2m, 4H,
61.85 (d, CH OP , J 7.8 Hz), 62.60 (d, C'H OP , J 7.0 Hz), 62.95
3
HH
2 1 CP 2 1 CP
2
2
p
Ph
5
2
1
4
6
1
2
1
CH ), 4.05 (m, 4H, 2CH ), 4.24 (d, 2H, 2HCP, J 17.3 Hz), 7.28 (m,
[d, (CH O) P , JCP 7.0 Hz)], 128.13 (d, C , J 3.0 Hz), 128.55
2
2
HP
2
2
2
CP
1
3
1
m
4
o
Ph
3
i
Ph
2
0H, 2Ph). C-{ H} NMR (150.9 MHz, CD CN) d: 16.53, 16.67 (2d,
(d, C
,
JCP 2.4 Hz), 128.84 (d, C , J 6.0 Hz), 135.72 (d, C , J
3
Ph
CP
CP
3
1
3
31
Me, J 5.5, 5.7 Hz), 59.94 (dd, CHP, J 151.5 Hz, J 10.4 Hz),
4.4 Hz). P NMR (CDCl ) d: 23.1 (s, P ), 27.8 (s, P ). IR (thin layer,
CP
CP
CP
3 1 2
3.43, 63.63 (2d, 4CH , J 6.8, 7.2 Hz), 128.67 (d, CPh, 5J 3.1 Hz),
2
p
n/cm ): 1027, 1053 (P–O–C), 1238 (P=O), 3389 (NH).
–1
2
CP
CP
m
o
Ph
3
i
Ph
2
29.06 (s, CPh), 129.51 (d, C , J 5.3 Hz), 137.57 (m, C
.3 Hz). P NMR (CD CN) d: 22.3 (s). IR (thin layer, n/cm ): 1024,
,
JCP
Elemental analysis of a mixture of 9c (d ) and 9c (d ), 1:1. Found (%):
CP
1
2
3
1
–1
C, 49.60; H, 7.53; N, 3.50; P, 14.76. Calc. for C H NO P (%): C,
3
17 31 6 2
040 (P–O–C), 1216, 1238 (P=O), 3342 (NH).
50.12; H, 7.62; N, 3.44; P, 15.23.
Mendeleev Commun. 2005 41

,
2005, 15(1), 40–42
diastereomers of compound 9c (d , downfield d , and d , upfield
The acid-catalysed addition of dialkyl phosphites 3 to imines 8
results in reaction products 9a–c.
1
p
2
2
0
dp) show considerably different [a] values, probably, due to
D
the stereoselectivity of formation of the P–C bonds (d :d = 1.4:1
The above scheme is in good agreement with the fact that the
chromatography of raw reaction products gave the following
1
2
for the reaction mixture).
¶
optically active by-products: iminophosphonate 8a, its hydro-
¶
*
2(R'O) PCl, H O
lysis product 10 and dialkyl phosphites 3.
2
2
PhCH NCHCOONa
–
NaCl
(
EtO)2P CH
N
CHPh
(EtO)2P CH NH ·HCl
2
R
1
1
a R = Ph
b R = Me
O
R
O
Ph
(
+)-8a
(–)-10
*
PhCH NCHCOP(OR')2
+
HCl
+
(R'O)2P(O)H
Thus, we found a new direction of the reaction of α-imino-
3
carboxylic acids with dialkyl chlorophosphites to give bis-
[
R
O
1-(dialkoxyphosphoryl)alkyl]amines. Taking into account that
2
7
α-aminophosphonates possess useful properties and display
O
N
R
R
N
O
8
various biological activities, the newly discovered direction is
*
also of practical interest. On the other hand, since the stereo-
controlling step of the suggested reaction scheme (5 ® 6,
Scheme 1) probably occurs via a six-membered transition state,
which is most favourable for attaining a high stereoselectivity,
this direction can serve as a basis for the development of the
synthesis of optically active α-aminophosphonates.
*
*
CH P(OR')2
(
R'O)2P CH
*
O
Ph
Ph
O
2
4
O
O
*
P(OR')2 Cl
HCl
PhCH NHCHCOP(OR')2
*
*
This study was supported by the R&D Foundation of the
Tatarstan Academy of Sciences (grant no. 07-7.2-235/2004).
Cl
R
O
R
N
H
Ph
5
6
References
H O – HCl
2
1
A. B. Smith, III, K. M. Yager and C. M. Taylor, J. Am. Chem. Soc.,
1995, 117, 10979.
O
*
[O]
*
*
2
M. N. Dimukhametov, M. A. Abackalova, E. Yu. Davydova, E. V. Bayandina,
A. B. Dobrynin, I. A. Litvinov and V. A. Alfonsov, Mendeleev Commun.,
2004, 35.
(
(
R'O)2P CH
N
CHR
(R'O)2P CH NH CHC
–
–
CO2
OH
H O
2
O
Ph
O
Ph
R
3
4
M. N. Dimukhametov, E. Yu. Davydova, E. V. Bayandina, A. B. Dobrynin,
I. A. Litvinov and V. A. Alfonsov, Mendeleev Commun., 2001, 222.
M. N. Dimukhametov, E. V. Bayandina, E. Yu. Davydova, I. A. Litvinov,
A. T. Gubaidullin, A. B. Dobrynin, T. A. Zyablikova and V. A. Alfonsov,
Heteroatom Chemistry, 2003, 14, 56.
8
7
3
, H+
*
*
R'O)2P CH NH CH P(OR')2
5
O. Gerngross and E. Zuhlke, Ber., 1924, 57, 1482.
O
Ph
R
O
6 K. Langheld, Ber., 1909, 42, 2360.
7
8
R. A. Cherkasov and V. I. Galkin, Usp. Khim., 1998, 67, 940 (Russ.
Chem. Rev., 1998, 67, 857).
Aminophosphonic and Aminophosphinic Acids. Chemistry and Bio-
logical Activity, eds. V. P. Kukhar and H. R. Hudson, John Wiley, New
York, 2000.
9
9
9
a R = Ph, R' = Et
b R = Ph, R' = Pr
i
c R = Me, R' = Et
Scheme 1
Most likely, this behaviour of imines 1a,b in reactions with
dialkyl chlorophosphites results from the high hygroscopicity
of α-iminocarboxylate salts. It is well known that the crystal
5
Received: 2nd July 2004; Com. 04/2316
lattice of such salts can contain several water molecules. Water
released during the reaction due to gradual dissolution of imines
hydrolyses a fraction of the dialkyl chlorophosphite. The HCl
formed reacts with iminoacylphosphites 2 and thus changes
the pathway of their subsequent conversions (Scheme 1). No
formation of 2,5-diketopiperazines 4 is observed in this case.
Immonium salts 5, similarly to iminoalkylphosphites,3 are
converted into phosphorus-containing amino acids 7 through a
two-step process involving a heterocyclisation step (intermediate
structure 6), which gives a P–C bond, and a dealkylation step
through the Arbuzov reaction followed by the hydrolysis of
¶
a: [a] D2 0 +7.10° (c 8.9, AcOEt). H NMR (600 MHz, CD CN) d:
1
8
3
3
1
.19, 1.20 (2t, 6H, 2Me, J 7.2 Hz), 2.29–2.39 (m, 4H, 2H C), 5.01
d, 1H, HCP, JHP 18.2 Hz), 7.32–7.84 (m, 10H, 2Ph), 8.47 (d, 1H,
HP
2
2
(
4
13
HC=N, JHP 4.8 Hz). C NMR (150.9 MHz, CD CN) d: 16.68, 16.73
3
2d, 2Me, 3J 5.6 Hz), 63.89, 64.07 (2d, 2CH , JCP 7.1 Hz), 73.72
2
(
C
P
2
,4
(d, CHP, 1J 152.1 Hz), 128.61 (d, CPhCP, JCP 3.1 Hz), 129.18 (d,
p
5
CP
m
PhCP
4
m
o
3
C
,
JCP 3.3 Hz), 129.19 (s, C
), 129.51 (d, C
), 136.97 (d, CPhCN, JCP 3.1 Hz),
, J 6.3 Hz),
PhCN
PhCP
CP
o
p
i
4
129.72 (s, C
), 132.23 (s, C
PhCN
PhCN
i
2
3
31
137.77 (d, CPhCN, JCP 7.6 Hz), 165.49 (d, CH=N, JCP 15.8 Hz). P NMR
(
(
–
1
CD CN) d: 19.8 (s). IR (thin layer, n/cm ): 1027, 1047 (P–O–C), 1249
3
P=O), 1639 (C=N).
acyl chlorides formed or by direct hydrolysis of intermediate
2
0
. The formation of compounds 7 was detected by 3 P NMR
1
10: mp 167–169 °C (from MeOH–MeCN, 2:1), [a]D –1.2° (c 1.1,
6
1
MeOH). H NMR (600 MHz, CD OD) d: 1.19, 1.29 (2t, 6H, 2Me,
3
spectroscopy. In the spectra of raw reaction mixtures, the signals
of the phosphorus atoms of compounds 7 are observed at
d 19 ppm. Upon removal of the solvent from the reaction mix-
tures and treatment of the residues in the presence of atmo-
spheric air, amino acids 7 are oxidised with simultaneous de-
carboxylation to iminophosphonates 8. The possibility of such
a behaviour of α-amino acids has been reported previously.6
3
JHH 7.0 Hz), 3.99, 4.08, 4.11 (3m, 4H, 2H CO), 4.84 (d, 1H, HCP,
2
2
3
m
p
o
JHP 17.8 Hz), 7.46 (br. m, 3H, 2H + 1HPh), 7.53 (br. d, 2H, 2H
,
Ph
Ph
13
1
JHH 7.1 Hz). C-{ H} NMR (150.9 MHz, CD OD) d: 15.40 (d, Me,
3
3J 5.6 Hz), 15.54 (d, C'H , J 5.1 Hz), 51.09 (d, CHP, J 155.1 Hz),
6
129.16 (s, C ), 129.76 (s, CPh), 129.96 (d, C
(CD OD) d: 17.6 (s).
3
1
CP
3
CP
CP
4.77, 64.93 (2d, 2CH OP, J 7.1 Hz), 128.42 (d, C , 3J 5.6 Hz),
2
o
2
CP
Ph
CP
31
m
Ph
p
i
Ph
2
, JCP 5.6 Hz). P NMR
3
The English language edited by Valentin V. Makhlyarchuk, Moscow
Typeset by Sergei I. Ososkov, Moscow
Printed in the UK by Page Bros, Norwich
4
2
Mendeleev Commun. 2005