N-Arylamides from Selenium-Catalyzed Reactions of Nitroaromatics
COMMUNICATIONS
Experimental Section
Typical Procedure for N-(6-Methoxy-3-
pyridyl)benzamide (4a)
Selenium (39.5 mg, 0.5 mmol), benzamide (1.22 g, 10 mmol),
2-methoxy-5-nitropyridine (1.54 g, 10 mmol), triethylamine
(2.02 g, 20 mmol), DBU (1.52 g, 10 mmol) and toluene
(10 mL) were successively loaded in a 100-mL stainless-steel
autoclave. The reactor was sealed, flushed with 1.0 MPa of car-
bon monoxide for three times, pressurized with 3.0 MPa car-
bon monoxide, and then placed in an oil bath preheated to
1608C. After the reaction was complete, the apparatus was
cooled to ambient temperature, and the remaining carbon
monoxide was evacuated. The reaction mixture was poured
into aqueous 1 N HCl (50 mL), and extracted with CH2Cl2
(3ꢀ50 mL). The organic phase was dried over MgSO4, filtered
and all the volatiles were evaporated under reduced pressure.
The resultant crude product was purified by flash column chro-
matography on silica gel (v/v, hexane/EtOAc¼5:1) to afford
4a as colorless needles; yield: 1.73 g (76%); mp 136–1388C
Scheme 4.
(Lit.: 139–1408C[12a]); IR (KBr): n¼3308 (nNꢁH), 1640 (nC O),
¼
1
1578, 1510, 1485, 1450 (nC
N), 1379 cmꢁ1 (nCH ); H NMR
¼
¼
C, C
(400 MHz, CDCl3, 238C): d¼3.90 (s, 3H, OCH3),36.71 (d, J¼
8.8 Hz, 1H), 7.42 (t, J¼7.6 Hz, 2H), 7.51 (t, J¼7.2 Hz, 1H),
7.84 (d, J¼7.6 Hz, 2H), 7.95 (dd, J¼8.8, 2.8 Hz, 1H), 8.07 (s,
1H, NH), 8.25 (s, 1H); 13C{1H} NMR (400 MHz, CDCl3,
238C): d¼53.75, 110.71, 127.23, 128.80, 131.99, 132.94,
134.50, 139.45, 161.38, 166.24.
Other products were identified by NMR and HPLC-MS
measurements and/or comparison with the authentic samples.
Acknowledgements
We acknowledge financial support from the Innovation Fund-
ing of Chinese Academy of Sciences, P. R. China.
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and DBU, a hydrogen source from water can be ration-
alized to promote formation of the product. Keeping
this in mind, 1.0 equiv. ofwater was applied in the reac-
tion of 1a and nitrobenzene, 8 was obtained in 39%
yield, demonstrating that water can be involved in for-
mation ofthe product.
In conclusion, we have demonstrated the first exam-
ples ofofrmal reductive acylation ofnitroaromatics
with amides in the presence ofselenium, CO, Et 3N and
DBU.
Adv. Synth. Catal. 2004, 346, 1267–1270
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