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DOI: 10.1055/s-0029-1217711
A Mild and Versatile Synthesis of Thioamides
Publikationsverlauf
Publikationsdatum:
31. Juli 2009 (online)
Abstract
Aliphatic and aromatic nitriles react with thioacetic acid in the presence of calcium hydride to give the corresponding thioamides in good to excellent yields. The examples studied include haloaryl nitriles in which the halogen is facile towards SNAr reactions under other conditions.
Key words
thioamides - nitriles - thioacetic acid - calcium hydride
- 1
Metzner P. Synthesis 1992, 1185 - 2
Herbert Haller LJ, andBarthel WF. inventors; US 2,358,925. - 3
Leresque CL. inventors; US 2,560,296. - 4 . inventors; Jpn. Kokai Tokyo 81 12 315.
-
5a
Jagodzinski TS. Chem. Rev. 2003, 103: 197 -
5b
Lawesson SO.Perregaard J.Scheibye S.Meyer HJ.Thompson I. Bull. Soc. Chim. Belg. 1977, 679 -
5c
Caddick S. SyntheticPages [Online] 2001, 66 ; http://www.syntheticpages.org/pages/66 -
6a
Kindler K. Justus Liebigs Ann. Chem. 1923, 431: 187 -
6b
Zbruyev OI.Stiasni N.Kapper CO. J. Comb. Chem. 2003, 5: 145 - 7
Brillion D. Synth. Commun. 1992, 1397 - 8
Albert A. Ber. Dtsch. Chem. Ges. 1915, 48: 470 -
9a
Gauthier JY.Lebel H. Phosphorus, Sulfur Silicon Relat. Elem. 1994, 325 -
9b
Ikeda K.Sato K.Nishino R.Aoyama S.Suzuki T.Sato M. Bioorg. Med. Chem. 2008, 16: 6783 - 10
Taylor EC.Zoltewicz JA. J. Am. Chem. Soc. 1960, 82: 2656 - 11
Liboska R.Zyka D.Bobek M. Synthesis 2002, 1649 -
12a
Yousif NM. Tetrahedron 1989, 45: 4599 -
12b
Pudovik AN.Cherkasov RA.Zimin MG.Zabirov NG. Bull. Acad. Sci. USSR Div. Chem. Sci. (Engl. Transl.) 1979, 28: 805 - 13
Benner SA. Tetrahedron Lett. 1981, 22: 1851 -
14a
Shiao MJ.Lai LL.Ku WS.Lin PY.Hwu JR. J. Org. Chem. 1993, 58: 4742 -
14b
Lin PY.Ku WS.Shiao MJ. Synthesis 1992, 1219 - 15
Boys ML.Downs VL. Synth. Commun. 2006, 295 - 16
Manaka A.Sato M. Synth. Commun. 2005, 761 - 17
Brillon D. Synth. Commun. 1992, 1397 - 18
Rapaport E.Cass MW.White EH. J. Am. Chem. Soc. 1972, 94: 3153 -
19a
Moghaddam FM.Hojabri L.Dohendou M. Synth. Commun. 2003, 4279 -
19b
Bagley MC.Chapaneri K.Glover C.Merritt EA. Synlett 2004, 2615 - 21
Sivakumar M.Senthilkumar P.Pandit AB. Synth. Commun. 2001, 2583 -
22a
Liboska R.Zyka D.Bobek M. Synthesis 2002, 1649 -
22b
Oliver JE.DeMilo AB.Cohen CF.Shortino TJ.Robbins WE. J. Agric. Food Chem. 1976, 24: 1065 -
22c
Takikawa Y.Shimada K.Sato K.Sato S.Takizawa S. Bull. Chem. Soc. Jpn. 1985, 58: 995 -
22d
Abdel-Lateef MF.-A.Eckstein Z. Bull. Acad. Pol. Sci., Ser. Sci. Chim. 1971, 19: 705 -
22e
Miwatashi S.Arikawa Y.Naruo K.Igaki K.Watanabe Y.Kimura H.Kawamoto T.Ohkawa S. Chem. Pharm. Bull. 2005, 53: 410 -
22f
Lin PY.Ku WS.Shiao MJ. Synthesis 1992, 1219 -
22g
Matsuda K.Yanagisawa I.Isomura Y.Mase T.Shibanuma T. Synth. Commun. 1997, 2393 -
22h
Sakai TT.Rama KN. Bioorg. Med. Chem. 1999, 7: 1559 -
22i
Chihiro M.Nagamoto H.Takemura I.Kitano K.Komatsu H.Sekiguchi K.Tabusa F.Mori T.Tominaga M.Yabuuchi Y. J. Med. Chem. 1995, 38: 353 -
22j
Kindler VK. Justus Liebigs Ann. Chem. 1927, 452: 107 -
22k
Erlenmeyer H.Junod J.Guex W.Erne M. Helv. Chim. Acta 1948, 31: 1342 -
22l
Lehr H.Guex W.Erlenmeyer H. Helv. Chim. Acta 1944, 27: 970 -
22m
Edward JT.Derdall GD.Wong SC. Can. J. Chem. 1977, 55: 2331
References and Notes
General Procedure
for the Synthesis of Thioamide
To a mixture of aryl
nitrile (1 equiv) and CaH2 (1 equiv) was taken in a two-necked
50 mL round-bottomed flask, and the content was cooled to 0 ˚C
and added thioacetic acid (1.5 equiv). After stirring for 15 min
the reaction mixture was heated in an oil bath at 80 ˚C
for the given period of time (Table
[¹]
).
After the completion of the reaction, the contents were cooled to
r.t., 50% aq EtOAc (2 × 10 mL)
was added and stirred for some time till the layers separated. Extraction was
done once again with EtOAc, and the combined organic layer was filtered
through Celite pad, and concentrated under reduced pressure to get
the crude product. It was then purified by crystallization using
PE and EtOAc (9:1). All the novel products were characterized by
NMR and MS analysis.
4-Bromo-2-chlorobenzenecarbothioamide
(2b)
¹H NMR (400 MHz, DMSO-d
6): δ = 7.31
(d, 1 H), 7.50 (q, 1 H), 7.75 (s, 1 H), 9.73 (br s, 1 H), 10.23
(br s, 1 H) ppm. ¹³C NMR (100 MHz,
DMSO-d
6): δ = 126.5,
129.1, 129.7, 133.3, 136.6, 141.3, 188.5 ppm. Anal. Calcd (%)
for C7H5BrClNS: C, 33.56; H, 2.01; N, 5.59.
Found: C, 33.54; H, 2.22; N, 5.55. MS: m/z = 251.0 [M+].
4-Chloro-3-nitrobenzenecarbothioamide (2d)
¹H
NMR (400 MHz, DMSO-d
6): δ = 7.8
(d, 1 H), 8.1 (d, 1 H), 8.5 (s, 1 H), 9.8 (br s, 1 H), 10.2 (br
s, 1 H) ppm.
¹³C NMR (100
MHz, DMSO-d
6): δ = 124.7,
128.0, 131.8, 132.4, 139.6, 147.2, 196.5 ppm. Anal. Calcd (%)
for C7H5ClN2O2S: C,
33.81; H, 2.33; N, 12.93. Found: C, 33.76; H, 2.38; N, 12.96. MS: m/z = 214.9 [M+].
2-(3,4-Dichlorophenyl)ethanethioamide (2f)
¹H
NMR (400 MHz, DMSO-d
6): δ = 3.8
(s, 2 H), 7.2 (d, 1 H), 7.5 (s, 1 H), 7.6 (d, 1 H), 9.4 (s, 1 H),
9.5 (s, 1 H) ppm. ¹³C NMR (100 MHz,
DMSO-d
6): δ = 50.5,
129.6, 129.8, 130.6, 131.1, 131.2, 138.8, 204.9 ppm. Anal. Calcd
(%) for C8H7Cl2NS: C,
43.65, H, 3.21, N, 6.36. Found: C, 43.76, H, 3.28, N, 6.34; MS: m/z = 219.9 [M+].
3-(4-Iodophenyl)propanethioamide (2g)
¹H
NMR (400 MHz, DMSO-d
6): δ = 3.7
(s, 2 H), 7.1 (d, 2 H), 7.6 (d, 2 H), 9.3 (br s, 1 H), 9.4 (br s,
1 H) ppm. ¹³C NMR: (100 MHz, DMSO-d
6): δ = 50.7,
93.0, 131.6, 137.3, 137.6, 205.4 ppm. Anal. Calcd (%) for
C8H8INS: C, 34.67; H, 2.91; N, 5.05. Found:
C, 34.65; H, 2.98; N, 5.11. MS:
m/z = 277.8 [M+].
2-[4-(Trifluoromethoxy)phenyl]ethanethioamide
(2i)
¹H NMR (400 MHz, DMSO-d
6): δ = 3.8
(s, 2 H), 7.2 (d, 2 H), 7.4 (d, 2 H), 9.4 (br s, 1 H), 9.5 (br s,
1 H) ppm. ¹³C NMR (100 MHz, DMSO-d
6): δ = 50.5,
116.7, 131.0, 131.3, 136.8, 137.3, 147.6, 147.7, 205.4 ppm. Anal.
Calcd (%) for C9H8F3NOS:
C, 45.95; H, 3.43; N, 5.95. Found: C, 45.98; H, 3.48; N, 5.98. MS: m/z = 235.8 [M+].
Propanethioamide (2t)
¹H
NMR (400 MHz, DMSO-d
6): δ = 1.2
(t, 3 H) 2.6 (q, 2 H), 7.2 (s, 1 H), 8.0 (s, 1 H) ppm. ¹³C
NMR (100 MHz, DMSO-d
6): δ = 15.0,
42.1, 208.6 ppm. Anal. Calcd (%) for C3H7NS: C,
40.41; H, 7.91; N, 15.71. Found: C, 40.45; H, 7.98; N, 15.78. GC-MS: m/z = 89.1 [M+].
2,2-Dimethylpropanethioamide (2v)
¹H
NMR (400 MHz, DMSO-d
6): δ = 1.3
(s, 9 H) 7.0 (br s, 1 H), 7.7 (br s, 1 H) ppm. ¹³C
NMR: (100 MHz, DMSO-d
6): δ = 32.5,
48.8, 221.8 ppm. Anal. Calcd (%) for C5H11NS:
C, 51.23; H, 9.46; N, 11.95. Found: C, 51.31; H, 9.48; N, 11.98. MS: m/z = 118.0 [M+].