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HETEROCYCLES, Vol. 65, No. 6, 2005
Ar – H ); LSIMS, m/z : 411 (M+), 393(M+-H2O), 367 (M+-CO2). Anal. Calcd for C22H16N3O2F3 : C,
64.23; H, 3.92; N, 10.21. Found: C, 64.33; H, 3.85; N, 10.35.
2,5,7-Trisubstituted 9-trifluoromethylpyrido[3',2':4,5]pyrrolo[3,2-d][1,3]oxazin-4(5H)- one ( 7 )
Compounds (6) (420 mg , 1 mmol) was taken in acetic anhydride ( 5 mL, 48 mmol )/trifluoroacetic
0
anhydride ( 5 mL, 34 mmol ) and the mixture was heated to 110 C (400C in case of trifluoroacetic
anhydride) while stirring for 2 h. The reaction mixture was cooled to rt and poured on to crushed ice. The
separated solid was filtered, washed with water until neutral to pH (7) and dried. The crude product was
purified by column using 60-120 mesh silica gel and the desired product was eluted with 10% CHCl3 in
hexane.
2-Methyl-5-benzyl-7-phenyl-9-trifluoromethylpyrido[3',2':4,5]pyrrolo[3,2-d][1,3]oxazin-4(5H)-one(7a)
Yield: 350 mg (79%), mp 282 0C, recrystallised from MeOH ; IR (KBr): 1751 ( C=O). 1H NMR(300 MHz,
CDCl3): δ 2.55 (3H, s, CH3 ), 6.0 ( 2H , s , CH2Ph ), 7.15 - 7.25 ( 4H, m, Ar-H ), 7.5 – 7.6 ( 4H, m, Ar- H ),
8.0 ( 1H , s , Ar – H ), 8.2 ( 2H , m , Ar – H ) ; MS (LSIMS), m/z : 437 (M++1), 392 (M+ - CO2 ) , 421 (M+
– CH3 ) ; Anal Calcd for C24H16N3O2F3: C, 66.21; H, 3.70; N, 9.65. Found: C, 66.15; H, 3.88; N, 9.78.
2,9-Bis(trifluoromethyl)-5-benzyl-7-phenylpyrido[3',2':4,5]pyrrolo[3,2-d][1,3]oxazin-4(5H)- one (7b)
Yield: 445 mg (87%) , mp 224 0C, recrystallised from MeOH ; IR (KBr): 1750 ( C=O). 1H NMR(300 MHz,
CDCl3): δ 6.05 ( 2H , s , CH2Ph ), 7.2 – 7.3 ( 4H, m, Ar-H ), 7.5 – 7.6 ( 4H, m, Ar- H ), 8.1 ( 1H , s , Ar –
H ), 8.20 - 8.25 ( 2H , m , Ar – H ); LSIMS, m/z : 490 (M++1), 420 ( M+- CF3 ) , 445 ( M+ - CO2 ) . Anal.
Calcd for C24H13N3O2F6: C, 58.90; H, 2.60; N, 8.59. Found: C, 58.84; H, 2.77; N, 8.66.
2-Methyl-5,7-diphenyl-9-trifluoromethylpyrido[3',2':4,5]pyrrolo[3,2-d][1,3]oxazin-4(5H)- one ( 7c)
Yield: 356 mg (78%), mp 266 0C, recrystallised from MeOH ; IR (KBr): 1755 ( C=O). 1H NMR(300 MHz,
CDCl3): δ 2.6 ( 3H , s , CH3 ), 7.3 - 7.4 ( 4H, m, Ar-H ), 7.5 - 7.6 ( 4H, m, Ar- H ), 8.0 - 8.05 ( 3H , m ,
Ar – H ) ; LSIMS, m/z : 422 (M+ + 1), 406 (M+ – CH3 ) , 377 ( M+ - CO2) . Anal. Calcd for C23H14N3O2F3:
C, 65.56; H, 3.35; N, 9.97. Found: C, 65.44; H, 3.28; N, 9.88.
2,9-Bis(trifluoromethyl)-5,7-diphenylpyrido[3’,2’:4,5]pyrrolo[3,2- d][1,3]oxazin- 4(5H)- one (7d )
Yield: 422 mg (85%), mp 268 0C, recrystallised from MeOH ; IR (KBr): 1752 (C=O). 1H NMR(300 MHz,
CDCl3): δ 7.4 – 7.6 ( 6H, m, Ar-H ), 7.75 - 7.8 ( 2H, m, Ar- H ), 7.9 ( 1H , s , Ar- H ), 8.0 - 8.05 ( 2H , m ,
Ar – H ) LSIMS, m/z : 476 (M++1), 406 (M+ – CH3 ) , 377 (M+– CO2 ) . Anal. Calcd for C23H11N3O2F6: C,
58.12; H, 2.33; N, 8.84. Found: C, 58.22; H, 2.45; N, 8.95
2-Methyl-5-phenyl-7-(4-chlorophenyl)-9-trifluoromethylpyrido[3',2':4,5]pyrrolo[3,2-d][1,3]oxazin-
4(5H)- one ( 7e )
Yield: 375 mg (82%), mp 274 0C, recrystallised from MeOH ; IR (KBr): 1784(C=O). 1H NMR(400 MHz,
CDCl3): δ 2.6 ( 3H , s , CH3 ), 7.45 ( 2H, m, Ar-H ), 7.5 - 7.6 ( 5H, m, Ar- H ), 7.9 - 8.0 ( 3H , m , Ar –
H ) . LSIMS, m/z ; 456 (M++1), 440(M+ – CH3 ) , 411 (M+ - CO2) . Anal. Calcd for C23H13N3O2ClF3 : C,
60.61; H, 2.87; N, 9.22. Found: C, 60.72; H, 2.95; N, 9.38.