358 Makowiec and Rachon
Reactions Between Sodium Diisopropyl
Phosphite 8 and Diacetoxyiodobenzene 2a
at Different Ratios
Preparation of Amides by Acylating System:
Diacyloxyiodobenzene 2 and PR1 12
3
To a solution of 2 (1 mmol) in 5 ml of chloroform,
To a suspension of NaH (1.1, 2.2, or 3.3 mmol) in
5 ml of THF, diisopropylphosphite (1, 2, or 3 mmol)
was added. When the evolution of hydrogen ceased,
2a (1 mmol, 0.322 g) was added. The reaction mix-
ture was stirred for 1 h at room temperature, the
solvent was removed in vacuum, and the residue
was dissolved in 30 ml of ether and extracted with
5% NaHCO3 water solution (2 × 10 ml). The or-
ganic layer was dried over MgSO4, filtered, and
evaporated. The residue was separated by chro-
matography on silica gel using acetone/CHCl3 as
eluent. The yields of iodobenzene and diisopropyl
1-(diisopropoxyphosphinyl)ethyl phosphate are pre-
sented in Table 2. The water layer was acidified with
conc HCl and extracted with ether (4 × 10 ml). The
collected ether solutions were dried over MgSO4, fil-
tered, and evaporated to give diisopropylphosphate.
PR1 (1 mmol) (triphenylphosphine, trimethylphos-
3
phite, or triisopropylphosphite) was added. Reaction
mixture was stirred at the boiling point of the sol-
vent for 1 h, and then benzylamine (2, 3, or 6 mmol)
was added. The reaction mixture was stirred for ad-
ditional 10 min, solvent was removed in vacuum, and
residue was dissolved in 30 ml in ether and extracted
with 5% NaHCO3 water solution (2 × 10 ml). The or-
ganic layer was dried over MgSO4, filtered, and evap-
orated. The residue was separated by chromatogra-
phy on silica gel using CH2Cl2/MeOH as eluent to give
1
amides. All amides were characterized by H NMR
and compared with authentic sample. Yields are pre-
sented in Table 3.
Carboxylic Acid Anhydrides 14
All products were characterized by 1H NMR and 31
NMR and compared with authentic sample. Unre-
acted amounts of PhI(OAc)2 in performed experi-
ments were estimated by iodometric titration.
P
To a solution of diacyloxyiodobenzene (1 mmol) in
5 ml of chloroform, trimethylphosphite (1 mmol,
0.124 g) was added. The reaction mixture was stirred
at the boiling point of the solvent for 1 h. The solvent
was removed in vacuum; the residue was disolved
in 30 ml of ether and extracted with 5% NaHCO3
water solution (2 × 10 ml). The organic layer was
dried over MgSO4 filtered, and evaporated to give
anhydride.
Run 15: diisopropyl 1-(diisopropoxyphosphinyl)-
ethyl phosphate (0.25 mmol, 0.094 g); 31P NMR
3
(CDCl3) δ = 19.67 (d, JPP = 35 Hz), −0.92 (d,
3 JPP = 35 Hz); Iodobenzene (0.51 mmol, 0.104 g).
Run 16: diisopropyl 1-(diisopropoxyphosphinyl)-
ethyl phosphate (0.51 mmol, 0.191 g); Iodoben-
zene (0.95 mmol, 0.193 g).
(S)-2-benzoylamino-3-methyl-butyric acid anhy-
dride (0.45 mmol, 0.190 g); 1H NMR (CDCl3) δ = 0.86
(d, 3 J = 6.78 Hz, 3H), 0.99 (d, 3 J = 6.83 Hz, 3H),
3
2.19–2.22 (m, 1H), 4.12 (d, J = 4.83 Hz, 1H), 7.26–
Run 17: diisopropyl 1-(diisopropoxyphosphinyl)-
ethyl phosphate (0.90 mmol, 0.336 g); Iodoben-
zene (0.9 mmol, 0.183 g).
7.34 (m, 3H), 7.38–7.42 (m, 1H), 7.84–7.88 (m, 2H).
3-tert-butoxycarbonylamino-propionic acid an-
1
hydride (0.23 mmol, 0.083 g); H NMR (CDCl3) δ =
3
3
1.36 (s, 9H), 2.62 (t, J = 5.86 Hz, 2H), 3.35 (t, J =
5.86 Hz, 2H), 7.63 (s, 1H).
Reactions Between Diacyloxyiodobenzene 2
2,4,6-trimethylbenzoic acid anhydride (0.95 mol,
0.294 g), m.p. 102–104◦C; 1H NMR (CDCl3) δ = 2.31
(s, 3H), 2.43 (s, 6H), 6.90 (s, 2H).
and PR1 12 in the Presence of Methanol
3
To a mixture composed of 2 (1 mmol) and methanol
(1, 3, 5, 10, 15 mmol) in 5 ml of chloroform, PR1
3
(1 mmol) (triphenylphosphine, trimethylphosphite,
or triisopropylphosphite) was added. The reaction
mixture was stirred at the boiling point of the solvent
for 1 h. Then the solvent was removed in vacuum, the
residue was dissolved in 30 ml of ether and extracted
with 5% NaHCO3 water solution (2 × 10 ml). The or-
ganic layer was dried over MgSO4, filtered, and evap-
orated. The residue was separated by chromatogra-
phy on silica gel using acetone/hexane as eluent to
give esters and anhydrides. All products were char-
acterized by 1H NMR and compared with authentic
samples. Yields are presented in Table 3.
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