A. Surana et al. / Journal of Organometallic Chemistry 646 (2002) 113–124
121
1
Hz, 1H, H-7). 13C-NMR (C6D6): l=11.5 (d, J=21.9
turned to pale yellow. It was allowed to stir overnight
and filtered. Removal of the solvent afforded a pale
yellow solid. Extraction with C6D6 (3 ml) gave a solu-
tion of 200 mg consisting of 5e and 1e, l31P 32.3 and
75.3, intensity ratio 1:1; crude yield of 5e 37%. The
solvent was evaporated and the residue extracted with
hot toluene as well as with hot hexane, but 1e enriched
in the filtrate (31P intensity ratio ca. 2:1) as well as in
the residue (31P intensity ratio ca. 4:1) which indicates
partial decomposition of 5e. (Addition of CD3OD con-
3
2
Hz, PMe), 30.9 (d, J=4.8 Hz, CMe3), 40.6 (d, J=
3
18.5, CMe3), 124.8 (C-7), 126.4 (d, J=6.5 Hz, C-5),
128.5 (d, 2J=19.8 Hz, C-4), 129.8 (C-6), 139.4 (d,
1J=3.0 Hz, C-3a), 158.8 (d, J=10.3 Hz, C-7a), 200.9
2
(d, J=38.0 Hz, C-2). 31P-NMR (C6D6): l= −11.6.
1
EIMS (70 eV); m/z (%): 206 (29), 205 (100) [M+], 204
(17), 190 (79) [M−15+], 163 (17), 149 (26), 148 (92)
[M−Bu+], 145 (24), 108 (12), 107 (44), 77 (12), 57 (20),
41 (14). Anal. Found: C, 69.67; H, 7.91; N, 6.90. Calc.
for C12H16NP (205.24): C, 70.23; H, 7.86; N, 6.82%.
1
verts 5e completely to 1e.) 5e. H-NMR (C6D6): l=
1.65 (d, 3JPH=14.5 Hz, 3H, MeCO), 2.13 (s, 3H,
3
Me-5), 7.02 (ddd, J=8.0, J=1.8, 0.6 Hz, 1H, H-6),
4.3.2. 2-Methyl-3-pentyl-1,3-benzazaphosphole (3a)
Compound 1a (460 mg, 3.08 mmol) was dissolved in
DMF (15 ml) and stirred at 20 °C with NaH (90 mg,
3.7 mmol) until the hydrogen evolution ceased (ca. 1 h).
On addition of pentylbromide (0.46, 3.7 mmol) to the
yellow solution the color turned immediately to pale
yellow. After stirring overnight toluene was added and
the solvent mixture removed in vacuo (twice repeated).
The residue is impure oily 3a, l31P 9.2, contaminated
by smaller amounts of 1a and side products with l31P
−11, −52, −72.
7.17–7.24 (m, Ph), 7.45 (m br, 1H, 4-H), 7.98 (d,
3J=8.1 Hz, 1H, H-7), 8.30 (dm, 2H, o-H). 13C-NMR
2
(C6D6): l=21.9 (Me-5), 34.6 (d, J=31 Hz, COMe),
124.8 (C-7), 130.7–130.9 (C-6, C-p, 2C-m), 130.9 (d,
3
2J=18.8 Hz, C-4, uncertain), 131.9 (d, J=13.5 Hz,
2C-o), 132.0 (C-5 superimposed), 137.1 (d, 2J=22.3
1
2
Hz, C-i ), 137.7 (d, J=8.1 Hz, C-3a), 158.4 (d, J=
1
7.9 Hz, C-7a), 175.6 (d, J=31.6 Hz, C-2), 210.2 (d,
1J=49.7 Hz, CO). 31P-NMR (C6D6): l=32.3.
4.3.5. 5-Methyl-2-phenyl-3-pi6aloyl-1,3-benzaza-
phosphole (6e)
4.3.3. p1(P)-(2-t-Butyl-3-methyl-1,3-benzaza-
1e (226 mg, 1.0 mmol) dissolved in Et2O (15 ml) was
lithiated with t-BuLi (0.59 ml, 1.7 M pentane solution,
1.0 mmol) at −78 °C. After 1 h at 20 °C the solution
was cooled again to −78 °C, and pivaloyl chloride
(0.123 ml, 1.0 mmol) was added with stirring. After
warming to r.t. (3 h) the orange–red color changes to
pale yellow. The mixture was allowed to stir overnight
and filtered. Removal of the solvent in vacuo (10−2
Torr) afforded a yellow oil which was extracted with
warm hexane to give 100 mg of pale yellow powder of
6e slightly contaminated by 1e. On cooling the filtrate
to −78 °C, 130 mg of pure 6e, m.p. 68–70 °C, was
collected; total yield ca. 230 mg (66%). 1H-NMR
(C6D6): l=0.93 (s, 9H, CMe3), 2.15 (s, 3H, Me-5), 7.02
phosphole)-pentacarbonyl-tungsten (4d)
2dLi was prepared from 2d (198 mg, 0.384 mmol) and
t-BuLi in pentane (0.20 ml, 0.384 mmol) as described
above. The solid was dissolved in Et2O (10 ml). Methyl
iodide (0.024 ml, 0.384 mmol) was added to this solu-
tion at −70 °C. After stirring at r.t. for 2 h the
precipitate was removed, and the solvent was evapo-
rated in vacuo. The residual solid was dissolved in a
small amount of THF. Addition of Et2O afforded an
orange precipitate which was dried for 2 h at 20 °C
yielding 190 mg of 4d containing a small amount of
1
LiI(Et2O)n (according to the H integral ratio 0.5Et2O
per mol 4d). 1H-NMR (THF-d8): l=1.53 (s, 9H,
2
CMe3), 2.05 (d, JPH=8.1 Hz, 3H, PMe), 7.43 (‘t’dd,
3
4
4
3J=7.4, JHH=1.1 Hz, JPH=3.6 Hz, 1H, H-5), 7.53
(ddd, J=8.0, J=1.8, 0.6 Hz, 1H, H-6), 7.17–7.24 (m,
3
(‘tt’, 3J=7.6, JHH:5JPH=1.1 Hz, 1H, H-6), 7.71,
4
3H, Ph), 7.58 (s m, JPH:2, J:1 Hz, 1H, 4-H), 7.94
(d, 3J=8.1 Hz, 1H, H-7), 8.27 (dm, 2H, o-H). 13C-
NMR (C6D6): l=22.0 (Me-5), 26.2 (d, 3J=3.4 Hz,
7.73 (2d, J=7.2, 7.3 Hz, 2H, H-7, H-4). 13C-NMR
3
(THF-d8): l=18.0 (d, 1J=21.7 Hz, PMe), 30.5 (d,
2
3J=2.1 Hz, CMe3), 40.7 (d, 2J=21.6 Hz, CMe3), 124.9
CMe3), 52.2 (d, J=28.3 Hz, CMe3), 125.1 (C-7), 129.5
4
3
3
(2C, C-6, C-p), 130.4 (d, J=7.9 Hz, 2C-m), 130.9 (d,
(d, J=3.0 Hz, C-7), 128.3 (d, J=8.9 Hz, C-5), 128.6
(d, 2J=14.9 Hz, C-4), 132.4 (d, 4J=1.2 Hz, C-6), 136.1
3
2J=19.9 Hz, C-4), 131.7 (d, J=18.4 Hz, 2C-o), 132.8
(d, 3J=3.4 Hz, C-5), 137.0 (d, 1J=7.1 Hz, C-3a), 138.1
(d, 2J=22.2 Hz, C-i ), 159.1 (d, 2J=7.4 Hz, C-7a),
179.7 (d, 1J=29.6 Hz, C-2), 216.1 (d, 1J=64.0 Hz,
CO). 31P-NMR (C6D6): l=22.7. EIMS (70 eV,
170 °C); m/z (%): 311 (48) [M++2], eventually by
reductive decomposition during heating, 310 (71), 255
(13), 244 (28), 232 (64) [M−Ph+], 231 (87), 230 (64),
188 (20), 148 (23), 121 (68) [MeC6H3P+], 86 (77) [t-
BuCO+], 77 (62), 57 (100) [t-Bu+]. Anal. Found: C,
73.61; H, 6.64; N 4.58. Calc. for C19H20NOP (309.35):
C, 73.77; H, 6.52; N, 4.53%.
1
2
(d, J=53.4 Hz, C-3a), 154.85 (d, J=19.7 Hz, C-7a),
1
2
192.2 (d, J=5.8 Hz, C-2), 197.1 (d sat, J=6.5 Hz,
1JCW=125.6 Hz, 4 CO), 198.9 (d, J=20.3 Hz, 1CO).
2
31P-NMR (THF-d8): l=3.4 (sat, JPW=216.9 Hz).
1
4.3.4. 5-Methyl-2-phenyl-3-acetyl-1,3-benzaza-
phosphole (5e)
Acetyl chloride (0.1 ml, 1.4 mmol) was added at
−78 °C to the orange–red solution prepared from 1e
(226 mg, 1.0 mmol) and t-BuLi (0.77 ml, 1.3 M pentane
solution, 1.0 mmol) in Et2O (10 ml) which immediately