3902
A. ZWIERZAK and S. ZAWADZKI
ring) cm'. The 'H NMR spectrum (CDCI,) showed sig-
nals at: 5= 1.35 (t, 6H, JH, 7.5Hz, C _H0 4.28 (qt, 4H, JH.~
'Jp~, 7.5H2, C H2), 4.75-5.27 (brs, IH, N H) 7-80 (s, 2H,
arom protons). The 3,p NMR spectrum (CHC13) showed a
signal at 8=- 1.60 ppm.
red oil (4.5g). Colourless needles (0.45g), which could be
isolated from this oil by successive washings with small
amounts of CCI,, melted at 144-148° and were identified
(m.mp., IR, NMR) as 6. The oily residue contained (GLC)
small amounts of diethyl phosphoroanilidate and con-
sisted mainly of 5 and 6.
Diethyl N,N-dibromophosphoramidate was prepared
by bromination of diethyl phosphoramidate)°
Generation and insertion of diethoxyphosphorylnitrene.
A mixture of 2 12.44g, 0.04 mole), freshly activated Zn
dust (7.80g,0.12 mole), and benzene (150 ml) was refluxed
gently with stirring for 15 hr. The resulting soln was then
filtered and the ppt washed with benzene (3x50 ml). The
filtrate was then washed with water (2 x 40 ml), dried and
evaporated to give a partially crystalline oil (l.30g). Col-
ourless needles (0.15g) which could be isolated from this
oil by filtration, m.p. 155-157", were identified (m.mp., IR,
NMR) as 6. GLC analysis showed the crude product to
contain a mixture of mono-, di-, and tribromobenzenes,
compound 6 (r, ,,, = I 1.0), small amounts of 4 (r, ~ = 1.0),
and 5 (r,,, =4.2). As determined by 3,p NMR spectros-
copy 6 amounted to 40% (by weight) of the crude product.
REFERENCES
'A. Ber~ho, T. Curtius and F. Schmidt, Bet. Dtsch. Chem.
Ges. 60, 1717 (1927); T. Curtius and F. Schmidt,/bid. 55,
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20. C. Dermer and M. T. Edmison, J. Am. Chem. Soc. 77,
70 (1955)
3.i.F. Heacock and M. T. Edmison Ibid. 82, 3460 (1960)
"R. A. Abramovitch, J. Roy and V. Uma, Canad. J. Chem.
43, 3407 (1965)
'R. A. Baldwin and R. M. Washburn, J. Org. Chem. 30,
386O (1965)
°K. D. Berlin and L. A. Wilson, Chem. Comm. 280 (1965)
~D. S. Breslow and M. F. Sloan, Tetrahedron Letters 5349
(1968)
Bromination of diethyl phosphoroanilidate
4 with
diethyl N,N-dibromophosphoroamidate (2). A mixture of
4 (2.29g, 0.01 mole), 2 (9.33g, 0.03 mole) and benzene
(100ml) was refluxed gently for 12 hr. The excess of un-
reacted 2 was removed with 20% NaHSO, aq (120 ml).
The organic phase was washed with water (3x50ml),
dried, and evaporated to give a partially crystalline dark-
"I. N. Zhmurova and A. V. Kirsanov, Zh. Obsh. Khim.
30, 4048 (1960)
9I-I. McCombie, B. C. Saunders and G. J. Stacey, J. Chem.
Soc. 380 (1945)
'°S. Zawadzki and A. Zwierzak, Tetrahedron 29, 315
(1973)
Zwierzak,A.
