Lithium hydroxide, monohydrate → HCID 86712486, compound

Participants

Reaction Steps

A solution of LiOH.H2O (1.319 g, 31.43 mmol) in water (20 mL) was added to a solution of the dihydrochloride 6 (2.443 g, 3.250 mmol) in methanol (80 mL). The mixture was stirred vigorously at room temperature for 3 h and then concentrated by evaporation. The residue was taken up in 80 ml of water and 4 ml of conc. hydrochloric acid were added. The reaction mixture was concentrated by evaporation once again and then taken up in 100 ml of water, added to a 4 cm×40 cm column packed with acidic Dowex 50WX2-200, washed with 1.5 L of water and then eluted with 1.5 L of 1N ammonia solution. The emerald green solution of 7, which was evaporated under reduced pressure at 50° C., was dried over phosphorus pentoxide overnight to give the dark brown powder 7 (2.0350 g, 96%). The powder was stirred in 20 ml of water at 70° C. for 20 min, cooled and centrifuged. The sediment was stirred in ice-cold water, centrifuged off and dried overnight over phosphorus pentoxide (1.1907 g). Melting point: 210-212° C. (decomposition). 1H NMR (300 MHz, [D6]-DMSO): δ=8.84 (s, 1H), 8.53 (d, J=9.0 Hz, 2H), 8.46 (d, J=9.0 Hz, 2H), 8.15 (br. s, 2H, 2 NH), 7.27 (s, 1H), 3.12 (m, 2H, 2 CHN; overlapping with HOD and NH2), 2.65 (t, J=7.5 Hz, 4H, 2 CH2N), 1.57-1.35 (m, 4H, 2 CH2), 1.30-1.00 (m, 8H, 4 CH2). HRMS (ESI): m/z [M+Na]+ calculated for C28H34N4NaO10S2 673.1614; found 673.1609; m/z [M−H]+ calculated for C28H33N4O10S2 649.1638; found 649.1644.

Provenance & Evidence