反应详情

3,5-Dioxo-2,3,4,5-tetrahydro-1,2,4-triazine (1 g) and 2-t-butoxytetrahydrofuran (1.9 g) are dissolved in dimethylformamide (3 ml), and the mixture is stirred at 160°-165° C. for 5 hours. The dimethylformamide is removed in vacuo from the reaction mixture to give the residue. The residue is column-chromatographed over silica gel using a mixture of acetone/n-hexane (1/3) as an eluent. The first major fraction gives 2,4-bis(tetrahydro-2-furanyl)-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine (Compound No. 85) (yield, 0.2 g; 12%), the second gives 3,5-dioxo-4-(tetrahydro-2-furanyl)-2,3,4,5-tetrahydro-1,2,4-triazine (Compound No. 86) (yield, 0.6 g; 36%) and the third gives 2-(tetrahydro-2-furanyl)-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine (Compound No. 101) (yield, 0.4 g; 24%). Compound Nos. 85 and 86 melt at 67°-68° C. and 87° C., respectively.

1. customThe dimethylformamide is removed in vacuo from the reaction mixture
2. customto give the residue
3. customThe residue is column-chromatographed over silica gel using
4. additiona mixture of acetone/n-hexane (1/3) as an eluent