Pyrimidine Derivatives. VIII. One-Step Synthesis of 3,4-Dihydro-pyrimido(6,1-c)(1,4)oxazine Derivatives by Reactions of 5-Bromo-1-(2-bromoethyl)-6-bromomethyl-2,4(1H,3H)-pyrimidinedione with Sodium Alkoxides and 2-Nitropropane.
The reaction of 5-bromo-1-(2-bromoethyl)-6-bromomethyl-3-methyl-2, 4(1H, 3H)-pyrimidinedione (1) with the sodium alkoxide/2-nitropropane system and that of the dinitrate (2) of 5-bromo-1-(2-hydroxyethyl)-6-hydroxymethyl-3-methyl-2, 4(1H, 3H)-pyrimidinedione with sodium alkoxide provide convenient routes to a wide range of 3, 4-dihydro-pyrimido[6, 1-c][1, 4]oxazine derivatives (3) in excellent yields.