FURFURYL ALCOHOL IN SYNTHESIS OF LEVULINIC ACID ESTERS
1689
t, CH2, J 6.3), 13C NMR ( , ppm): 27.47 (C-2), 29.39
(CH3), 37.65 (C-3), 51.37 (OCH3), 173.03 (COO),
206.40 (CO). Mass spectrum, m/z (Irel, %): 130 [M]+
(10), 43 (96), 45 (7), 51 (1), 53 (3), 55 (57), 57
(38), 59 (40), 60 (4), 70 (2), 71 (32), 75 (6), 76 (1),
81 (4), 83 (1), 87 (25), 88 (45), 89 (3), 90 (0.5), 98
(44), 99 (100), 100 (10), 101 (2), 110 (0.5), 115
(98), 116 (6), 117 (2), 120 (0.5).
O
2
CH2OH
H2O
O
1
O
O
8
CH2O
O
O
7
D10-Methyl levulinate 6. Yield 40%. 13C NMR
EXPERIMENTAL
1
(CDCl3; , ppm): 27.09 (C-2, JCD 19.7 Hz), 37.15
The H and 13C NMR spectra of the compounds in
CDCl3 were recorded on a JEOL FX90Q spectrometer
[90 MHz (1H), 22.5 MHz (13C)]; the chemical shifts
(ppm) are given relative to TMS. The IR spectra
were recorded on a UR-20 spectrophotometer in KBr
pellets or in thin layer (film), and mass spectra, on
a Finnigan MAT-112S chromatograph-mass spec-
trometer (EU, 70 eV). Chromatographic analysis was
performed on a Chrom-5 device; 1.2 m 3 mm col-
umn, stationary phase SE-30 (5%) on Chromaton
N-AW-HMDS, heating from 50 to 250 C at a rate
1
1
1
(C-3, JCD 19.8 Hz), 29.00 (CH3, JCD 19.1 Hz),
1
50.23 (OCH3, JCD 19.3 Hz), 172.89 (COO), 206.40
(CH3CO). Mass spectrum, m/z (Irel, %): 140 [M]+ (2),
44 (7), 45 (34), 46 (100), 57 (17), 61 (14), 62 (23),
76 (10), 77 (8), 92 (8), 93 (14), 95 (25), 96 (8),
102 (9), 103 (13), 104 (45), 105 (28), 106 (6), 119
(2), 120 (42), 121 (59), 122 (9), 129 (2), 130 (1),
138 (4), 139 (2), 140 (2).
Ethyl levulinate 3. Yield 95%, bp 73 74 C/
6 mm Hg (bp 205 208 [18]). 1H NMR spectrum
(CDCl3; , ppm; J, Hz): 1.25 (3H, t, CH3, J 5.7),
2.17 (3H, s, COCH3), 2.50 (2H, t, CH2, J 5.5),
2.66 (2H, t, CH2, J 6.3), 4.12 (2H, q, CH2, J 6.1),
13C NMR ( , ppm): 28.32 (C-2), 36.95 (C-3), 29.52
(CH3), 58.67 (OCH2), 12.13 (CH3), 171.52 (COO),
204.44 (CH3CO). Mass spectrum, m/z (Irel, %): 144
[M]+ (5), 43 (100), 45 (7), 55 (8), 71 (10), 73 (15),
74 (20), 98 (13), 99 (80), 101 (24), 102 (22), 129 (30).
1
1
of 8 deg min , carrier gas helium (47 ml min ).
The hypochlorite concentration was determined by
iodometric titration [15].
As the starting reactants we used commercially
available alcohols: furfuryl alcohol, methanol, ethanol,
propanol, and isopropanol, which were prepurified by
distillation. Carbon tetrachloride was purified by
the standard procedure.
Isopropyl levulinate 4. Yield 85%, bp 86 87 C/
10 mm Hg (bp 209 203 C [18]). Mass spectrum, m/z
(Irel, %): 158 [M]+ (0.3), 41 (12), 43 (93), 71 (8),
73 (7), 74 (29), 98 (5), 99 (100), 101 (19), 116 (13),
117 (15), 130 (3), 143 (7), 144 (0.2).
Commercial iron acetylacetonate Fe(acac)3 was
recrystallized and dried in a vacuum desiccator before
use; Rh(PPh3)3Cl was synthesized by the procedure
described previously and dried in a vacuum (20 h,
80 C) [16, 17].
Propyl levulinate 5. Yield 80%, bp 95 96 C/
The general procedure for synthesis of levulinic
acid was as follows. A reactor (V = 100 ml) was
charged with 0.1 mmol of Fe(acac)3, 10 mmol of
furfuryl alcohol, 40 mmol of aliphatic alcohol, and
20 mmol of CCl4. The reaction was carried for 3.5 4 h
at 70 C with continuous stirring. Then the reactor
was cooled to room temperature and the reaction
mixture was filtered through a silica gel bed (eluent
hexane : ether = 1 : 1). The solvent was removed,
and the residue was distilled.
1
10 mm Hg (bp 221 222 C [18]). H NMR spectrum
(CDCl3; , ppm; J, Hz): 0.94 (3H, t, CH3, J 5.2),
1.50 1.83 (2H, m, CH2), 2.22 (3H, s, CH3), 2.50
3.18 (4H, m, CH2), 4.05 (2H, t, CH2, J 5.5). 13C
NMR ( , ppm): 29.59 (C-5, CH3), 26.82 (C-2), 37.14
(C-3), 64.69 (OCH2), 19.92 (CH2), 8.59 (CH3),
58.67 (OCH2), 12.13 (CH3), 170.68 (COO), 204.77
(CH3CO). Mass spectrum, m/z (Irel, %): 158 [M]+
(0.3), 43 (99), 71 (12), 73 (14), 74 (21), 98 (18),
99 (100), 101 (31), 129 (39).
The structure of the resulting compounds was con-
firmed by spectral data and also by comparison with
authentic samples and reference data.
To synthesize difurylmethane, 0.1 mmol of Wil-
kinson complex Rh(PPh3)3Cl, 10 mmol of furfuryl
alcohol, 40 mmol of water, and 20 mmol of CCl4
were placed in a 100-ml reactor. The reaction mix-
ture was heated with continuous stirring and kept for
6 h at 70 C. After cooling to room temperature,
the reaction mixture was filtered through a silica gel
Methyl levulinate 2. Yield 98%, bp 76 C/
10 mm Hg (bp 196 C [18]). 1H NMR spectrum
(CDCl3; , ppm; J, Hz): 3.66 (3H, s, CH3), 2.19
(3H, s, COCH3), 2.56 (2H, t, CH2, J 5.5), 2.70 (2H,
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 80 No. 10 2007