T. Mizuno et al. / Tetrahedron 58 (2002) 7805–7808
7807
isocyanate as an intermediate by the elimination of
hydrogen sulfide from the carbamate salt (3a) might be
impossible. Reported urea derivative synthesis from
primary aliphatic amines with carbon monoxide and sulfur,
in which an isocyanate is a key intermediate was performed
under pressurized carbon monoxide and high tempera-
(75 MHz, d -DMSO) d 47.4, 76.3, 125.8, 128.4, 128.7,
6
139.5, 158.7; MS (m/z, %) 163 (M , 92), 107 (100), 79 (64);
þ
Exact MS calcd for C H NO : 163.0633. Found: 163.0614.
9
9
2
4.2.3. 5-Methyl-2-oxazolidone (1c). Oil; IR (neat) 3300,
1745, 1245 cm2 ; H NMR (300 MHz, d -DMSO) d 1.28
1 1
6
2
0,21
ture.
(d, J¼6 Hz, 3H), 3.01 (t, J¼8 Hz, 1H), 3.54 (t, J¼8 Hz, 1H),
1
3
4.59–4.66 (m, 1H), 7.37 (brs, 1H); C NMR (75 MHz,
d -DMSO) d 20.3, 46.5, 72.2, 158.9; MS (m/z, %) 101 (M ,
þ
6
3. Conclusion
100), 86 (26), 73 (13), 56 (27); Exact MS calcd for
C H NO : 101.0477. Found: 101.0462.
4
7
2
A useful synthetic method for 2-oxazolidinones (1) by the
thiocarboxylation of 2-aminoethanols (2) with carbon
monoxide using elemental sulfur, followed by the oxidative
cyclization with molecular oxygen was developed. From
the viewpoint of application to actual industrial production
of 2-oxazolidinone (1) as intermediates of medicines or
agricultural chemicals, the present preparative method is
very significant, using cheap and easily available carbon
monoxide, sulfur, and oxygen, and mild reaction conditions
4.2.4. 4-Ethyl-2-oxazolidone (1d). Oil; IR (neat) 3275,
1 1
1750 cm2 ; H NMR (300 MHz, d
-DMSO) d 0.79–0.89
(m, 3H), 1.38–1.47 (m, 2H), 3.62–3.71 (m, 1H), 3.83–3.91
6
1
3
(m, 1H), 4.29–4.37 (m, 1H), 7.73 (brs, 1H); C NMR
(75 MHz, d -DMSO) d 9.0, 27.7, 52.9, 68.8, 158.9; MS
6
þ
(m/z, %) 115 (M , 22), 86 (100), 85 (24), 58 (20); Exact MS
calcd for C
H NO : 115.0633. Found: 115.0609.
5 9 2
2
3
(
1 atm, rt).
4.2.5. 2-Imidazolidone (1e). Mp 129.18C (1318C ); IR
1
(
KBr) 3305, 1670, 1275 cm2
d6-DMSO) d 3.26 (s, 4H), 6.11 (brs, 2H); C NMR
;
1
H NMR (300 MHz,
3
1
þ
4. Experimental
(75 MHz, d
100), 85 (12), 58 (4).
6
-DMSO) d 40.2, 164.4; MS (m/z, %) 86 (M ,
4
.1. General
4
.2.6. 4-Methyl-2-imidazolidone (1f). Mp 118.28C (120–
2
4
21
1
Melting points were determined on a Mettler FP 5
instrument and were uncorrected. FT-IR spectra were
1228C ); IR (KBr) 3215, 1695, 1260 cm
(300 MHz, d
-DMSO) d 1.08 (d, J¼6 Hz, 3H), 2.72–2.88
(m, 1H), 3.34–3.40 (m, 1H), 3.63–3.69 (m, 1H), 6.06 (brs,
1H), 6.26 (brs, 1H); C NMR (75 MHz, d -DMSO) d 21.2,
þ
47.4, 47.5, 163.3; MS (m/z, %) 100 (M , 84), 85 (100).
; H NMR
6
1
recorded on a Nicolet Magna-IR 550 instrument. H and
1
3
13
C NMR spectra were obtained on a JEOL JNM-AL300
300, 75 MHz) instrument. Chemical shifts were reported
6
(
in ppm relative to tetramethylsilane (d-units). Mass and
exact mass spectra were recorded on a JEOL JMS-600
spectrometer. 2-Aminoethanols (2a–d), ethylene-diamines
4.2.7. 2-Thiazolidone (1g). Oil; IR (neat) 3255, 1675 cm2
1
;
1
H NMR (300 MHz, d
3.46 (t, J¼7 Hz, 2H), 7.94 (brs, 1H); C NMR (75 MHz,
-DMSO) d 3.36 (t, J¼7 Hz, 2H),
6
1
3
(
2e,f), 2-aminoethanethiol (2g), DMF, DME, THF, bases,
sulfur (99.5%), carbon monoxide (99.9%), and oxygen
99.5%) were used as purchased.
þ
d
-DMSO) d 29.4, 42.8, 173.7; MS (m/z, %) 103 (M , 100),
H NOS: 103.0092.
3 5
6
(
60 (84), 59 (40); Exact MS calcd for C
Found: 103.0064.
4
(
.2. Typical procedure for synthesis of oxazolidinone
1a)
A DMF solution (20 mL) containing powdered sulfur
641 mg, 20 mmol), 2-aminoethanol (2a) (1.21 mL,
0 mmol) and K CO (2.76 g, 20 mmol) was vigorously
stirred under carbon monoxide (1 atm) at 208C for 4 h. After
the carbonylation, carbon monoxide was purged and
molecular oxygen was charged. The reaction mixture was
stirred vigorously for additional 2 h under 1 atm of oxygen,
References
(
2
1. Henry, C. M. Chem. Engng News 2000, 41–58.
2. Madar, D. J.; Kopecka, H.; Pireh, D.; Pease, J.; Pliushchev,
M.; Sciotti, R. J.; Wiedeman, P. E.; Djuric, S. W. Tetrahedron
Lett. 2001, 42, 3681–3684.
3. R u¨ ck-Braun, K.; Stamm, A.; Engel, S.; Kunz, H. J. Org.
Chem. 1997, 62, 967–975.
2
3
2
08C. Than, evaporation of solvent, followed by purification
by short column-chromatography (AcOEt/MeOH, 1:1),
4. Wuts, P. G. M.; Pruitt, L. E. Synthesis 1989, 622–623.
5. Kn o¨ lker, H.-J.; Braxmeier, T. Tetrahedron Lett. 1998, 39,
gave 2-oxazolidone (1a) (1.52 g, 87%) as a pure form.
9
407–9410.
22
4
.2.1. 2-Oxazolidone (1a). Mp 87.98C (88–898C ); IR
2
6. Kubota, Y.; Kodaka, M.; Tomohiro, T.; Okuno, H. J. Chem.
Soc., Perkin Trans. 1 1993, 5–6.
1
1
(
KBr) 3270, 1735, 1255 cm
;
H NMR (300 MHz,
d -DMSO) d 3.43 (t, J¼8 Hz, 2H), 4.27 (t, J¼8 Hz, 2H),
7. Suzuki, M.; Yamazaki, T.; Ohta, H.; Shima, K.; Ohi, K.;
Nishiyama, S.; Sugai, T. Synlett 2000, 189–192.
8. Sibi, M. P.; Renhowe, P. A. Tetrahedron Lett. 1990, 31,
6
1
3
7
1
.42 (brs, 1H); C NMR (75 MHz, d -DMSO) d 40.0, 64.2,
6
þ
59.6; MS (m/z, %) 87 (M , 100), 59 (79).
7
407–7410.
4
3
3
.2.2. 5-Phenyl-2-oxazolidone (1b). Mp 83.68C; IR (KBr)
2
9. Ishimaru, T. Nippon Kagaku Zasshi 1960, 81, 1589–1592.
10. Pridgen, L. N.; Prol, Jr. J.; Alexander, B.; Gillyard, L. J. Org.
Chem. 1989, 54, 3231–3233.
1 1
280, 1715, 1240 cm ; H NMR (300 MHz, d -DMSO) d
6
.39 (dd, J¼9, 7 Hz, 1H), 3.93 (t, J¼9 Hz, 2H), 5.64 (t,
1
3
J¼8 Hz, 2H), 7.39–7.49 (m, 5H), 7.73 (brs, 1H); C NMR
11. Tamura, O.; Hashimoto, M.; Kobayashi, Y.; Katoh, T.;