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M. GULLU AND D. YIGIT
1886
saturated sodium carbonate to pH 7–8. Afterwards, the oily product was extracted
with chloroform (150 mL), which was dried with Na2SO4, filtered, and removed on a
rotary evaporator. Residual light-brown solid product was purified by recrystallization
from acetone (94.5%). Mp 80–85 ꢀC. IR (KBr): nmax 3082, 3010, 2984, 2822, 1770, 1662,
1631, 1569, 1515, 1450, 1384, 1336, 1230, 1178, 1097, 972, 920, 858, 814, 741, 685 cmꢁ1
.
1H NMR (400 MHz, CDCl3) d 3.0 (t, J ¼ 7.2 Hz, 2H, -CH2-), 4.15 (t, J ¼ 7.2 Hz, 1H, -
=
CH), 5.23 (dd, J ¼ 10.4 Hz-cis and J ¼ 1.2 Hz, 1H, -CH C-), 5.32 (dd, J ¼ 14.8 Hz-
=
=
trans and J ¼ 1.2 Hz, 1H, CH C-), 5.95 (m, 1H, C CH-), 7.84 (s, 4H, Ph-H).
General Procedure for the Synthesis of 6-Substituted 3-Allyl-
2-hydroxy-4H-pyrido[1,2-a]pyrimidin-4-ones (3a–e)
2-Aminopyridine derivative (1a–c, 2.0 mmol) and bis(2,4,6-trichlorophenyl)
allylmalonate (2, 2.0 mmol) were dissolved in 10 mL acetone containing triethylamine
(0.4 mL). After stirring 1 h at room temperature, the reaction was complete. The solid
product was filtered under a vacuum and recrystallized from EtOH=H2O (1:3).
Selected Data for 3a–3c
2-Hydroxy-6-methyl-3-(prop-2-en-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one
(3a). Yellow solid (81%). Mp 226–230 ꢀC. IR (ATR): nmax 3073, 3034, 2878–2284,
2990, 2874, 1683, 1648, 1621, 1592, 1502, 1446, 1352, 1371, 1257, 1180, 982, 899,
1
800 cmꢁ1. H NMR (400 MHz, CDCl3) d 3,1 (s, 3H, 6-CH3), 3.25 (d, J ¼ 6 Hz,
=
2H, -CH2-), 5.0 (dd, J ¼ 11. 0 Hz-cis, 1H, -C CH-), 5.4 (dd, J ¼ 18.0 Hz-trans, 1H,
=
=
-C CH), 6.0 (m, 1H, -CH C-), 6.82 (d, J ¼ 6.8 Hz, 1H, 7-CH), 7.42 (d, J ¼ 8.0 Hz,
Hz, 1H, 9-CH), 7.66 (t, J ¼ 8.0 Hz, 1H, 8-CH). MS (EI) m=z calcd. for C12H12N2O2
216.2; found 216 (Mþ, 50), 201 (5), 188 (25), 173 (10), 159 (10), 149 (10), 135 (100),
119 (5), 108 (20), 92 (55). Elemental analysis: anal. calcd. for C12H12N2O2 (216.23):
C,65.65; H, 5.59; N, 12.96. Found: C, 66.30; H, 5.52; N, 12.82.
6-Amino-2-hydroxy-3-(prop-2-en-1-yl)-4H-pyrido[1,2-a]pyrimidin-4-one
(3b). Light green solid (87%). Mp 286–290 ꢀC (dec). IR (ATR): nmax 3317, 3259,
3184, 3130, 3028, 2880–2388, 2972, 2911, 2851, 1671, 1617, 1574, 1511, 1448,
1
1386, 1336, 1151, 1082, 995, 908, 843, 770 cmꢁ1. H NMR (400 MHz, DMSO-d6)
d 2.96 (d, J ¼ 6.4 Hz, 2H), 3.4 (broad signal, 2H, -NH2), 4.84 (dd, J ¼ 11.0 Hz-cis,
=
=
=
1H, -C CH-), 4.98 (dd, J ¼ 18.0 Hz-trans, 1H, -C CH-), 5.56 (m, 1H, -CH C-),
6.2 (d, J ¼ 8.0 Hz, 1H, 7-CH), 6.25 (d, J ¼ 8.0 Hz, 1H, 9-CH), 7,5 (t, J ¼ 8.0 Hz,
1H, 8-CH). MS (EI) m=z calcd. for C11H11N3O2 217.2; found 217 (Mþ, 100), 202
(100), 188 (5), 170 (20), 147 (5), 118 (5), 109 (5), 94 (5), 77 (5). Elemental analysis:
anal. calcd. for C11H11N3O2 (217.22): C, 60.82; H, 5.10; N, 19.34. Found: C,
60.45; H, 5.08; N, 19.30.
6-Acetylamino-2-hydroxy-3-(prop-2-en-1-yl)-4H-pyrido[1,2-a]pyrimidin-
4-one (3c). Green solid (85%). Mp 250–252 ꢀC (dec). IR (ATR): nmax 3192–2162,
3131, 3079, 3130, 2999, 2973, 2909, 1699, 1641, 1628, 1587, 1386, 1371, 1270,
1
1235, 1174, 1034, 997, 902, 794 cmꢁ1. H NMR (400 MHz, DMSO-d6) d 2.28 (s,
=
3H, -CH3), 3.28 (d, J ¼ 6.4 Hz, 2H, CH2-), 5.05 (dd, J ¼ 11,0 Hz-cis, 1H, -C CH-),
=
=
5.18 (dd, J ¼ 18,0 Hz-trans, 1H, -C CH-), 6.0 (m, 1H, -CH C-), 7,12 (d, J ¼ 8.0 Hz,