Electrophilic Nitration of Electron-Rich Acetophenones
1605
was stirred at ꢂ25ꢁC for 3 h and hyrolyzed with 30cm3 H2O. The organic layer was washed with 5%
aqu. K2CO3, dried (CaCl2) and evaporated under reduced pressure. The products were purified by
column chromatography and recrystallized.
Method E [18]
Acetophenone (10 mmol) was dissolved in 30cm3 CH2Cl2 before Claycop (mixture of Cu(NO2)2 ꢄ H2O
and Montmorillonite K10 (26=30)) (10 mmol) and 9.40cm3 of acetic anhydride (100 mmol) were
added. The mixture was stirred for 16 h at room temperature. The solution was filtered and evaporated
under reduced pressure. The products were purified by column chromatography and recrystallized.
4-Acetyl-2-methoxy-N-methylaniline (2, C10H13NO2)
Sodium hydride was added at room temperature to a solution of 3-hydroxy-4-methylaminoacetopheno-
ne [25] (0.5g, 30mmol) in THF. After stirring for 30min, 0.23 cm3 of iodomethane (36mmol) were
added. After 24 h, the mixture was poured into 50cm3 H2O and extracted with ether. The organic layer
was dried (CaCl2) and evaporated under reduced pressure to give 0.33 g of orange solid (61%).
Mp 105–106ꢁC (cyclohexane); 1H NMR (300 MHz, DMSO-d6): ꢀ ¼ 2.55 (s, 3H, COCH3), 2.90 (d, 3H,
J ¼ 4.9 Hz, NCH3), 3.90 (s, 3H, OCH3), 4.85 (bs, 1H, NH), 6.50 (d, 1H, J ¼ 8.3 Hz, H-5), 7.40 (dd, 1H,
J ¼ 1.6 Hz, H-2), 7.55 (dd, 1H, J ¼ 8.3Hz, 1.6 Hz, H-6); IR (KBr): ꢁꢀ¼ 3381, 1649 cmꢂ1
6-Acetyl-3-methyl-4-nitro-3H-benzoxazol-2-one (4, C10H8N2O5)
.
Yellow solid; chromatography eluent: CH2Cl2, petroleum ether 1=1; Rf ¼ 0.5 (CH2Cl2); Mp 175–
1
176ꢁC (EtOH); H NMR (300MHz, CDCl3): ꢀ ¼ 2.65 (s, 3H, COCH3), 3.70 (s, 3H, NCH3), 8.05
(d, 1H, J ¼ 1.6 Hz, H-7), 8.45 (d, 1H, J ¼ 1.6 Hz, H-5); IR (KBr): ꢁꢀ¼ 1760, 1680 cmꢂ1
.
2-Acetoxy-4-acetyl-3,5-dinitro-N-methylaniline (11, C11H11N3O7)
Yellow solid; chromatography eluent: EtOAc, cyclohexane 1=1; Rf ¼ 0.7 (EtOAc); Mp 155–156ꢁC
(EtOH 95%); 1H NMR (300 MHz, CDCl3): ꢀ ¼ 1.97 (bs, 1H, NH), 2.36 (s, 3H, COCH3), 2.71 (s, 3H,
COCH3), 3.24 (s, 3H, NCH3), 8.36 (s, 1H, H-5); IR (KBr): ꢁꢀ¼ 1715, 1685, 1535, 1345cmꢂ1; MS
(70 eV): m=z ¼ 297 (Mþ).
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