ORDER
REPRINTS
3292
ZHOU AND CHEN
(60 mg, 0.05 mmol), DMF (6 mL) and dialkyl phosphonate (0.2 mL,
1.2 mmol) was stirred at 90ꢀC for 2 h under nitrogen atmosphere, then
diluted with saturated aqueous NH4Cl (20mL) and extracted with ether
(15 mL Â 3). The combined organic layer was washed with brine and dried
over anhydrous Na2SO4. After the removal of the solvent in vacuum, the
residue was isolated by TLC with c-hexane-EtOAc (2 : 1) as developer to
give pure dipropyl phenylphosphonate (3a) 235 mg, 98% yield.
Spectroscopic Data for the Product
Dipropyl phenylphosphonate 3a: oil, bp 115ꢀC/2 Torr (lit13 bp
106–108ꢀC/1 Torr), 1H NMR, dH 0.9 (t, 6H), 1.6 (m, 4H), 3.9 (m, 4H),
7.6 (m, 3H), 7.9 (m, 2H). IR (film), nmax 1255 (P¼O), 1030 (P-O-C),
980cm À1 (Ar-P).
Diethyl phenylphosphonate 3b: oil, bp 112ꢀC/2 Torr (lit2 bp
96–98ꢀC/0.2 Torr), H NMR, dH 1.28 (t, 6H), 4.13 (m, 4H), 7.7 (m, 3H),
1
8.1 (m, 2H). IR (film), nmax 1250, 1030, 965 cmÀ1
.
Diisopropyl phenylphosphonate 3c: oil, bp 131ꢀC/2 Torr (lit2 bp
1
96–97ꢀC/0.1 Torr), H NMR, dH 1.25 (m, 12H), 4.6 (m, 2H), 7.5 (m, 3H),
7.8 (m, 2H). IR (film), nmax 1250, 1010, 980 cmÀ1
.
Dibutyl phenylphosphonate 3d: oil, 154ꢀC/2 Torr (lit14 166ꢀC/
3.8 Torr), 1H NMR, dH 0.85 (t, 6H), 1.5 (m, 8H), 3.95 (m, 4H), 7.5 (m, 3H),
7.85 (m, 2H). IR (film), nmax 1250, 1025, 970 cmÀ1
.
Diethyl p-tolylphosphonate 3e: oil, 179ꢀC/2 Torr (lit2 bp 118–119ꢀC/
0.05 Torr), 1H NMR, dH 1.23 (t, 6H), 2.33 (s, 3H), 4.1 (m, 4H), 7.3 (m, 2H),
7.7 (m, 2H). IR (film), nmax 1250, 1030, 970 cmÀ1
.
Dipropyl p-tolylphosphonate 3f: oil, 120ꢀC/2 Torr (lit13 bp 110–112ꢀC/
1
1 Torr), H NMR, dH 0.88 (t, 6H), 1.55 (m, 4H), 2.35 (s, 3H), 3.9 (m, 4H),
7.3 (m, 2H), 7.72 (m, 2H). IR (film), nmax 1250, 1050, 990 cmÀ1
.
Diisopropyl p-tolylphosphonate 3g: oil, 118ꢀC/2 Torr (lit13
98–100ꢀC/1 Torr), H NMR, dH 1.25 (m, 12H), 2.35 (s, 3H), 4.6 (m, 2H),
1
7.25 (m, 2H), 7.7 (m, 2H). IR (film), nmax 1250, 1010, 980 cmÀ1
.
Dibutyl p-tolylphosphonate 3h: oil, 164ꢀC/2 Torr (lit15 148ꢀC/
1
0.7 Torr), H NMR, dH 0.88 (t, 6H), 1.4 (m, 8H), 2.37 (s, 3H), 4.0 (m, 4H),
7.35 (m, 2H), 7.75 (m, 2H). IR (film), nmax 1250, 1010, 970 cmÀ1
.
Diisopropyl p-chlorophenylphosphonate 3i: oil, 145ꢀC/2 Torr (lit16 oil,
bp was not reported) 1H NMR, dH 1.25 (m, 12H), 4.6 (m, 2H), 7.25–7.9 (m,
4H). IR (film), nmax 1250, 1020, 980 cmÀ1
.
Dipropyl p-chlorophenylphosphonate 3j: oil, 142ꢀC/2 Torr (lit17
148.5ꢀC/3 Torr), 1H NMR, dH 0.9 (t, 6H), 1.6 (m, 4H), 3.9 (m, 4H),
7.22–7.9 (m, 4H). IR (film), nmax 1250, 1020, 980 cmÀ1
.