Abstract
A new and facile synthetic method for urea derivatives was developed under mild conditions,
and contrasts with conventional preparation methods that need highly toxic reagents
(phosgene) or severe reaction conditions. In our reaction system, N,N-dimethylformamide or dimethyl sulfoxide as solvent strongly accelerated the carbonylation
of primary amines with sulfur under carbon monoxide (1 atm) at 20 °C to give the corresponding
thiocarbamate salts. These salts were readily oxidized by molecular oxygen under similarly
mild conditions to afford urea derivatives in good to excellent yields. This urea
synthesis could also be applied to a new synthesis of aromatic ureas by use of 1,8-diazabicyclo[5.4.0]undec-7-ene
in N,N-dimethylformamide.
Key words
amines - amides - sulfur - carbonylations - oxidations
References
<A NAME="RF04506SS-1">1</A>
Papesch V.
Schroeder EF.
J. Org. Chem.
1951,
16:
1879
<A NAME="RF04506SS-2">2</A>
Clark RL.
Pessolano AA.
J. Am. Chem. Soc.
1958,
80:
1657
<A NAME="RF04506SS-3">3</A>
The reaction of isocyanates with amines 2 is a typical synthetic method for the preparation of urea derivatives. However, isocyanates
are also prepared from phosgene and primary amines 2.
<A NAME="RF04506SS-4">4</A>
Pfaendler HR.
Weisner F.
Heterocycles
1995,
40:
717
<A NAME="RF04506SS-5">5</A>
Cortez R.
Rivero IA.
Somanathan R.
Aguirre G.
Ramirez F.
Hong E.
Synth. Commun.
1991,
21:
285
<A NAME="RF04506SS-6">6</A>
Staab HA.
Angew. Chem.
1956,
68:
754
<A NAME="RF04506SS-7">7</A>
Staab HA.
Justus Liebigs Ann. Chem.
1957,
609:
75
<A NAME="RF04506SS-8">8</A>
Beaver DJ.
Roman DP.
Stoffel PJ.
J. Am. Chem. Soc.
1957,
79:
1236
<A NAME="RF04506SS-9">9</A>
Ayyangar R.
Chowdhary AR.
Kalkote UR.
Nath AA.
Chem. Ind.
1988,
599
<A NAME="RF04506SS-10">10</A>
Fox JJ.
Van Praag D.
J. Am. Chem. Soc.
1960,
82:
486
<A NAME="RF04506SS-11">11</A>
Davoll J.
Laney DH.
J. Chem. Soc.
1960,
314
<A NAME="RF04506SS-12">12</A>
Mavrovic I. In
Kirk-Othmer Encyclopedia of Chemical Technology
Vol. 21:
Mark HF.
Wiley Interscience;
New York:
1970.
p.37
<A NAME="RF04506SS-13">13</A>
Ogura H.
Takeda K.
Tokue R.
Kobayashi T.
Synthesis
1978,
394
<A NAME="RF04506SS-14">14</A>
Cooper CF.
Falcone SJ.
Synth. Commun.
1995,
25:
2467
<A NAME="RF04506SS-15">15</A>
Sasaki Y.
Nippon Kagaku Kaishi
1996,
109
<A NAME="RF04506SS-16">16</A>
Fournier J.
Bruneau C.
Dixneuf PH.
Lecolier S.
J. Org. Chem.
1991,
56:
4456
<A NAME="RF04506SS-17">17</A>
Baiocchi F.
Franz RA.
Horwitz L.
J. Org. Chem.
1956,
21:
1546
<A NAME="RF04506SS-18">18</A>
Bassoli A.
Rindone B.
Tollari S.
Chioccara F.
J. Mol. Catal.
1990,
60:
41
<A NAME="RF04506SS-19">19</A>
Giannoccaro P.
J. Organomet. Chem.
1987,
336:
271
<A NAME="RF04506SS-20">20</A>
Choudary BM.
Rao KK.
Pirozhkov SD.
Lapidus AL.
Synth. Commun.
1991,
21:
1923
<A NAME="RF04506SS-21">21</A>
Franz RA.
Applegath F.
J. Org. Chem.
1961,
26:
3304
<A NAME="RF04506SS-22">22</A>
Franz RA.
Applegath F.
Morriss FV.
Baiocchi F.
J. Org. Chem.
1961,
26:
3306
<A NAME="RF04506SS-23">23</A>
Franz RA.
Applegath F.
Morriss FV.
Baiocchi F.
Bolze C.
J. Org. Chem.
1961,
26:
3309
<A NAME="RF04506SS-24">24</A>
Sonoda N.
Yasuhara T.
Kondo K.
Ikeda T.
Tsutsumi S.
J. Am. Chem. Soc.
1971,
93:
6344
<A NAME="RF04506SS-25">25</A>
Sonoda N.
Pure Appl. Chem.
1993,
65:
699
<A NAME="RF04506SS-26">26</A>
Mizuno T.
Matsumoto M.
Nishiguchi I.
Hirashima T.
Heteroat. Chem.
1993,
4:
455
<A NAME="RF04506SS-27">27</A>
Mizuno T.
Iwai T.
Ishino Y.
Tetrahedron
2005,
61:
9157
<A NAME="RF04506SS-28">28</A>
Mizuno T.
Daigaku T.
Nishiguchi I.
Tetrahedron Lett.
1995,
36:
1533
<A NAME="RF04506SS-29">29</A>
In the previous report
[25]
of urea synthesis from primary amines and carbon monoxide with the use of a selenium
catalyst, the same reaction pathway was suggested.
<A NAME="RF04506SS-30">30</A>
NMR data are not reported, as measurement of NMR spectra was difficult because of
the very low solubility of 1h in organic solvents.
<A NAME="RF04506SS-31">31</A>
Boivin PA.
Bridgeo W.
Boivin JL.
Can. J. Chem.
1954,
32:
242
