反应详情

A suspension of 6-methylisocytosine (0.98 g, 7.8 mmol), and 2-isocyanatoethyl methacrylate (2.20 g, 14.1 mmol) in dry pyridine (35 mL) was heated under reflux for 2 h, giving a clear solution. Cooling induced the formation of crystals. Acetone was added (20 mL), and the resulting microcrystalline powder was filtered. Recrystallization from ethanol/CHC13 (1:1, v/v) gave analytically pure product (1.62 g, yield is 74%) 1H NMR (400 MHz, CDCl3) 13.00 (s, 1H, intramol H-bonding), 11.97 (s, 1H, CH2—NH—CO), 10.53 (s, 1H, CH2—NH—CO—NH), 6.20 (s, 1H, CHH.═.C), 5.80 (s, CCH3CH—CO), 5.56 (s, 1H, CHH═C), 4.31-4.28 (t, J=5.6, 2H, OCH2CH2N), 3.62-3.58 (q, J=5.6 Hz, 2H, OCH2CH2N), 2.26 (s, 3H, CH3—C—NH), 1.96 (s, 3H, CH3—C═CH2), IR (neat) 3250-2800, 1726, 1699, 1664, 1641, 1583, 1521, 1253, 1172, 939 cm−1; Melting point Tm=206.7° C.

1. temperaturewas heated
2. temperatureunder reflux for 2 h
3. customgiving a clear solution
4. temperatureCooling
5. filtrationthe resulting microcrystalline powder was filtered
6. customRecrystallization from ethanol/CHC13 (1:1