Pyrimidine-Annelated Heterocycles
1191
The CHCl3 solution was washed with 20 cm3 saturated Na2SO3 solution, 2 Â 25cm3 H2O, and dried
ꢀNa2SO4). Removal of CHCl3 gave a gummy residue which was puri®ed by column chromatography
on silica gel. Elution of the column with benzene:ethylacetate 9:1 gave 7b which was recrystallized
from CHCl3=petroleum ether.
1
Yield: 85% ꢀ0.26 g); white solid; m.p.: 147ꢀC; H NMR ꢀCDCl3, ꢀ, 300 MHz): 1.56±2.20 ꢀm,
H-4,5,6,7,8,9), 3.30 ꢀs, 3H, N±CH3), 3.36 ꢀs, 3H, N±CH3), 3.54 ꢀq, H-3, J 6 Hz), 4.36 ꢀddd,
H-1, J 4.6, 6, 10Hz), 5.13 ꢀt, H-2, J 6 Hz) ppm; IR ꢀKBr): ꢁ 1180, 1490, 1650, 2960cmÀ 1
;
UV=Vis ꢀEtOH): ꢂmax 218, 264 nm; MS: m=z 362 ꢀM ).
8-ꢀ30-Chlorobenzoyloxy)-1,3-dimethyl-hexahydrobenzofuro[2,3-d]
pyrimidine-2,4-dione ꢀ6; C19H19ClN2O5)
m-Chloroperbenzoic acid ꢀ50%; 0.51 g, 1.5 mmol) was added to 0.35g 3 ꢀ1.5mmol) in 30 cm3 thio-
phene-free dry benzene, and the mixture was re¯uxed for 12 h. The reaction mixture was extracted with
2 Â 25cm3 benzene, washed with 2 Â 30cm3 NaHCO3 solution and 2 Â 25cm3 H2O, and dried
ꢀNa2SO4). The solvent was removed, and the residue was subjected to column chromatography on
silica gel. 6 was obtained when the column was eluted with ethylacetate:benzene 1:3.
Yield: 85% ꢀ0.49 g); white solid; m.p.: 198ꢀC; 1H NMR ꢀCDCl3, ꢀ, 300 MHz): 1.62±1.76 ꢀm, 6H),
2.68 ꢀm, H±Cꢀ4b)), 3.36 ꢀs, 3H, N±CH3), 3.38 ꢀs, 3H, N±CH3), 3.99 ꢀbr s, H±Cꢀ8)), 4.06 ꢀbr s, H±
Cꢀ8a)), 7.43 ꢀt, 1H, J 8 Hz), 7.59±7.61 ꢀm, 1H), 7.94 ꢀd, 1H, J 8 Hz), 8.01 ꢀt, 1H, J 1.6 Hz) ppm;
13C NMR ꢀCDCl3, ꢀ, 100 MHz): 29.54 ꢀC-1), 168.48 ꢀC-2), 29.60 ꢀC-3), 165.25 ꢀC-4), 19.76, 20.34,
27.22 ꢀC-5, C-6, C-7), 70.0 ꢀC-8a), 44.91 ꢀC-4b), 80.79 ꢀC-9a), 150.9 ꢀC-4a), 167.6 ꢀC-ester carbonyl),
129.87 ꢀC-10), 130.50 ꢀC-20), 135.26 ꢀC-30), 134.75 ꢀC-40), 130.41 ꢀC-50), 128.73 ꢀC-60) ppm; IR ꢀK Br):
ꢁ 1170, 1450, 1660, 1730, 2960, 3020 cmÀ 1; UV=Vis ꢀEtOH): ꢂmax 234 nm; MS: m=z 390,
392 ꢀM ).
1,3-Dimethyl hexahydro bicyclo[3.3.1]benzopyrano[2,3-d]
pyrimidine-2,4-dione ꢀ7d; C12H16N2O3)
0.35g of 3 ꢀ1.5mmol) were added in portions to 2 cm3 conc. H2SO4 at 0±5ꢀC, and the mixture was
stirred for 2 h at this temperature. The solution was then poured into crushed ice and extracted with
3 Â 25cm3 CHCl3. The organic layer was washed with 3Â10cm3 5% Na2CO3 solution, 3 Â 20cm3
H2O, and dried ꢀNa2SO4). Evaporation of CHCl3 gave a gummy mass which was puri®ed by column
chromatography on silica gel. Elution of the column with benzene:ethylacetate 3:1 gave 7d which
was recrystallized from CHCl3=petroleum ether.
1
Yield: 60% ꢀ0.21 g); white solid; m.p.: 92ꢀC; H NMR ꢀCDCl3, ꢀ, 300MHz): 1.37±2.11 ꢀm,
H-2,3,5,6,7,8,9,10), 3.17 ꢀbr s, H-4), 3.33 ꢀs, 3H, N±CH3), 3.36 ꢀs, 3H, N±CH3), 4.85 ꢀbr s, H-1)
ppm; IR ꢀKBr): ꢁ 1190, 1470, 1640, 2970 cmÀ 1; UV=Vis ꢀEtOH): ꢂmax 217, 264 nm; MS: m=z
236 ꢀM ).
Acknowledgement
We thank the CSIR ꢀNew Delhi) for the ®nancial assistance. S. K. Samanta is grateful to CSIR
ꢀNew Delhi) for a fellowship.
References
[1] For previous papers in this series see a) Majumdar KC, Das U ꢀ1998) J Org Chem 63: 9997;
b) Majumdar KC, Das U, Jana NK ꢀ1998) J Org Chem 63: 3550
[2] Heidelberger C ꢀ1984) In: Holland JF, Frei E, Febiger L ꢀeds) Pyrimidine and Pyrimidine
Antimetabolites in Cancer Medicine. Lea Febiger, Philadelphia, pp 801