Unexpected reaction pathway of tert-butyl tetraethylphosphorodiamidite with benzyl chloride [3]

Full text of DOI:10.1023/A:1023427732128

Russian Journal of General Chemistry, Vol. 72, No. 12, 2002, pp. 1953 1954. Translated from Zhurnal Obshchei Khimii, Vol. 72, No. 12, 2002,
pp. 2061 2062.
Original Russian Text Copyright
2002 by Sal’keeva, Nurmagambetova, Kurmanaliev.
LETTERS
TO THE EDITOR
Unexpected Reaction Pathway of tert-Butyl
Tetraethylphosphorodiamidite with Benzyl Chloride
L. K. Sal’keeva, M. T. Nurmagambetova, and O. Sh. Kurmanaliev
Buketov Karaganda State University, Karaganda, Kazakhstan
Received March 6, 2002
Amides and amidoesters of P(III) acids react with
alkyl halides with participation of the unshared elec-
tron pair of the phosphorus atom and formation of
quasiphosphonium compounds. In the presence of
alkoxy groups on phosphorus, the products are
capable to undergo transformation according to the
second stage of the Arbuzov reaction [1, 2].
(diethylamide) (II). In nonpolar and polar solvents,
much diethylamine hydrochloride is formed along
with compound II. Other reaction products are iso-
butylene and ( -chlorobenzyl)phosphonous diethyl-
amide (III),
8 ppm, JPH 580 Hz. The IR spectrum
P
of compound III contains a P H absorption band at
1
2370 cm . Evidently, this reaction is described by a
scheme involving the Arbuzov rearrangement com-
peting with the initial protonation of the phosphorus
atom, leading to an ionic or a pentacovalent quasi-
phosphonium compound which can further transform
along several pathways.
We are the first to find that tert-butyl tetraethyl-
phosphorodiamidite (I) reacts with benzyl chloride in
different ways depending on reaction conditions. The
reaction in the absence of solvent involves primarily
the Arbuzov reaction leading to benzylphosphonic bis-
Benzylphosphonic bis(diethylamide) (II), bp
153 154 C (0.5 mm), mp 80 81 C. Published data
[3]: mp 82 83.5 C.
( -Chlorobenzyl)phosphonous
diethylamide
(III), mp 137 138 C. 31P NMR spectrum:
8 ppm
P
1
(JPH 580 Hz). IR spectrum, , cm : 2370 (P H),
1070-3632/02/7212-1953$27.00 2002 MAIK Nauka/Interperiodica

1954
SAL’KEEVA et al.
1220 (P=O). Found, %: C 53.29; H 7.15; N 5.23; P
12.48; Cl 14.78. C11H17ClOP. Calculated, %: C 53.77;
H 6.92; N 5.70; P 12.63; Cl 14.46.
REFERENCES
1. Razumov, A.I., Tr. Kazan. Khim.-Tekhnol. Inst., 1957,
vol. 23, p. 201.
The IR spectra were recorded on a Specord IR-75
1
2. Hudson, R.F. and Searle, R.J.G., Chimia, 1966, vol. 20,
spectrometer in thin layer. The H NMR spectra were
no. 4, p. 117.
measured on
a
Bruker WP-80 spectrometer
(32.44 MHz) against external H3PO4
3. JP Patent 48-40740, Ref. Zh. Khim., 1974, 18N684P.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 72 No. 12 2002