4-Methylmorpholine → N-[(E)-3-(3-Methyl-4-oxo-1-n-propyl-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-6-yl)-4-n-propoxy-cinnamoyl]morpholine

Participants

Reaction Steps

To a stirred solution of (E)-3-(3-methyl-4-oxo-1-n-propyl-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-6-yl)-4-n-propoxycinnamic acid (Example 13; 1.0 g, 0.0025 mol) and morpholine (0.21 g, 0.0025 mol) in dichloromethane at 0° C. was added, sequentially, N-methylmorpholine (0.5 g, 0.005 mol), 1-hydroxybenzotriazole hydrate (0.383 g, 0.0025 mol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.957 g, 0.005 mol). The reaction mixture was allowed to warm to room temperature, stirred for 20 hours and evaporated under vacuum, then the residue partitioned between water (30 ml) and dichloromethane (30 ml). The organic phase was removed and the aqueous phase extracted with more dichloromethane (2×30 ml); the combined organic solutions were then dried (Na2SO4 and the solvent removed under vacuum to give a white solid. Purification by column chromatography (SiO2, CH2Cl2 then 3% MeOH in CH2Cl2) and crystallisation from ethyl acetate-hexane-methanol afforded the title compound as white crystals (0.74 g, 63%), m.p. 156-157° C. Found: C, 64.60; H, 6.85; N, 15.16. C25H31N5O4 requires C, 64.50; H,, 6.71; N, 15.04%.

Provenance & Evidence