4890
S. R. Narahari et al. / Tetrahedron Letters 52 (2011) 4888–4891
Table 1 (continued)
Entry
Oximes
OH
Amides
Reaction time (h)
Conversion (%)
O
N
HN
14
10
85
O2N
O2N
All the products were characterized by NMR and compared with the reported data.15
CH3
N
CH3
N
O
CH3
CH3
O
O
Cl
H3C
N
H3C
+
Cl
H
O
Cl
1
HO
R2
N
CH3
N
CH3
N
R1
R1
N
N
R2
R2
-DMF
R1
Cl
-H
Cl
H3C
H3C
O
O
N
H
N
R2
R1
R2
R1
3
4
2
H2O
R2
O
N
R1
H
Figure 1. Proposed mechanism.
Encyclopedia of Chemical Processing and Design In Mcketta, J. J., Ed.; Marcel
Dekker: New York, 1978; pp 72–95.
The hydroxyl group of the oxime adds to Vilsmeier–Haack-type
complex to form the cationic species 1. The subsequent rearrange-
ment to adduct 2 then affords directly the nitrile, in the case of
aldoximes, or the amide upon hydrolytic work-up. The conversion
of 2–4 proceeds through a concerted 1,2 intramolecular shift.
In conclusion, a mild, general and efficient conversion of oximes
to corresponding amides has been developed. The key feature of
this method is the use of pivaloyl chloride/DMF as a mild, non-
toxic and inexpensive reagent. This method seems to be conve-
nient with respect to other existing reports and can be used as
an alternative, which will avoid tedious purifications or the use
of toxic or expensive reagents.
4. Izumi, Y.; Sato, S.; Urabe, K. Chem. Lett. 1983, 12, 1649–1652.
5. Chandrasekhar, S.; Gopalaiah, K. Tetrahedron Lett. 2003, 44, 755.
6. Chandrasekhar, S.; Gopalaiah, K. Tetrahedron Lett. 2002, 43, 2455.
7. Wang, B.; Gu, Y.; Luo, C.; Yang, T.; Yang, L.; Suo, J. Tetrahedron Lett. 2004, 45,
3369.
8. Li, D.; Shi, F.; Guo, S.; Deng, Y. Tetrahedron Lett. 2005, 46, 671.
9. De Luca, L.; Giacomelli, G.; Porcheddu, A. J. Org. Chem. 2002, 67, 6272.
10. Antikumar, S.; Chandrasekhar, S. Tetrahedron Lett. 2000, 41, 5427.
11. (a) Heravi, M. M.; Khadijeh, B.; Hekmat Shoar, R.; Oskooie, H. A. J. Chem. Res.
2005, 590; (b) VenkatNarsaiah, A.; Nagaiah, K. Adv. Synth. Cat. 2001, 346, 1271;
(c) Lee, K.; Han, S.-B.; Yoo, E.-M.; Chung, S.-R.; Oh, H.; Hong, S. Synth. Commun.
2001, 34, 1775; (d) Konwar, D.; Boruah, R. C.; Sandhu, J. S. Tetrahedron Lett.
1990, 31, 1063.
12. (a) Katritzky, A. R.; Zhang, G. F.; Fan, W. G. Org. Prep. Proced. Int. 1993, 25, 315;
(b) Olah, G. A.; Narang, S. C.; Garcia-Luna, A. Synthesis 1980, 659; (c) Sosnovsky,
G.; Krogh, J. A. Synthesis 1978, 703; (d) Sacdnya, A. Synthesis 1983, 748; (e)
Molina, P.; Alajarian, M.; Vilaploma, M. J. Synthesis 1982, 1016.
13. (a) Li, W. C.; Lu, A. H.; Palkovits, R.; Schmidt, W.; Spliethoff, B.; Schuth, F. J. Am.
Chem. Soc. 2005, 127, 12595; (b) Ichihashi, H.; Kitamura, M. Catal. Today 2002,
73, 23; (c) Srinivas, K. V. N. S.; Reddy, E. B.; Das, B. Synlett 2002, 625; (d)
Fernandez, A. B.; Boronat, M.; Blasco, T.; Corna, A. Angew. Chem., Int. Ed. 2005,
44, 2370.
14. General Procedure: A mixture of pivaloyl chloride (0.18 g, 1.5 mmol) and DMF
(1 mL) was stirred at room temperature for 1 h. To the mixture was first added
CH2Cl2 (5 mL) followed by oxime (0.113 g, 1.0 mmol). The reaction was
monitored (TLC) until the complete disappearance of starting material.
Water (5 mL) was added, and then the organic phase was washed with 3 mL
of a saturated solution of Na2CO3, followed by 1 N HCl and brine. The organic
Acknowledgments
S.R.N. and B.R.R. thank Inogent Laboratories Private Ltd,
Hyderabad and S.R.N. and M.K. thank J.N.T. University, Hyderabad.
References
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caprolactam.
e-
15. Compounds data:
e-Caprolactam: mp. 73–74 °C.
Acetanilide: mp. 114–115 °C
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N-(2-Hydroxyphenyl)acetanilide: mp. 209–210 °C; 1H NMR d 9.11 (bs, 1H), 8.80
(s, 1H), 7.42 (m, 1H), 7.02 (m, 2H), 6.90 (m, 1H), 2.24 (s, 3H); 13C NMR d 170.0,
148.2, 126.8, 125.1, 121.6, 116.4, 23.3.
N-(3-Hydroxyphenyl)acetanilide: mp. 148–149 °C; 1H NMR d 9.30 (bs, 1H), 8.97
(s, 1H), 7.30 (s, 1H), 7.05 (t, 1H), 6.88 (d, 1H), 6.54 (d, 1H), 2.10 (s, 3H); 13C NMR