7-amino-2-(2-furyl)-5-[2-(4-hydroxyphenyl)ethyl]amino[1,2,4]-triazolo[1,5-a][1,3,5]triazine (0.91 g) and 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU, 0.37 ml) were added to a suspension of 7-amino-2-(2-furyl)-5-methylsulphonyl-[1,2,4]triazolo[1,5-a][1,3,5]triazine (0.82 g) in acetonitrile (50 ml) and the resulting mixture was heated under reflux for 17 hours, after which time thin layer chromatography (TLC) analysis on silica plates (eluent: methylene chloride-methanol 19:1 v/v) indicated that no methanesulphonyl starting material remained. The solvent was then evaporated and the residue was purified by column chromatography on silica (75 g) eluting with ethyl acetate-methylene chloride 7:3 v/v. A white solid was obtained, and this was crystallised from isopropanol to afford 7-amino-5-[4-(2-[7-amino-2-(2-furyl)-[1,2,4]triazolo[1,5-a][1,3,5]triazin-5-ylamino]ethyl)phenoxy]-2-(2-furyl)[ 1,2,4]triazolo[1,5-a][1,3,5]triazine, m.p. 285°-289° C.; microanalysis, found: C, 54.1; H, 4.4; N, 30.8%; C24H19N13O3 1.0(C3H7OH) requires: C, 54.2; H, 4.5; N, 30.5%; NMR: 2.92 (t, 2H, phenyl-CH2), 3.55 (q, 2H, CH2-N), 6.67 (m, 2H, 2 furyl-4H), 7.0 (d, 1H, furyl-3H), 7.11 (d, 1H, furyl-3'H), 7.16 and 7.35 (A2B2 pattern, 4H, phenyl-H), 7.5 (br t, 1H, NH rotamers), 7.85 (d, 1H, furyl-5H), 7.89 (d, 1H, furyl-5'H), 8.12 (br s, 2H, NH2) and 8.93 (d, 2H, NH2); m/e (M+H)+ 538.
