Formaldehyde → HCID 89807019, compound

Participants

Reaction Conditions

Reaction Steps

Compound i (1.68 g, 4.89 mmol) was suspended in MeOH (65 mL) and formaldehyde (37 wt % in H2O, 7.94 g, 97.9 mmol) then methylamine (2 M in MeOH, 24.5 mL, 49 mmol) added. The suspension was heated to 80° C. for 5 h. H2O was added and the mixture extracted with EtOAc and then DCM. The organic layers were dried (Na2SO4), filtrated and concentrated in vacuo to give a residue that contained 1-(5-azido-7-bromo-1,3-benzothiazol-2-yl)-3-ethyl-5-methyl-1,3,5-triazinan-2-one (1.31 g). A part of this mixture (827 mg; 2.09 mmol) was suspended in DMF (36 mL), cooled down at 0° C. and then treated with 3,3-diethoxyprop-1-yne (535 mg, 4.17 mmol), DIPEA (320 mg, 2.5 mmol) and CuI (70 mg; 0.37 mmol). The ice bath was removed and the reaction let to stir overnight at RT. The mixture was freeze-dried and the residue purified by chromatography on silica (0-5% MeOH gradient in DCM) to give a residue that was triturated with EtOAc affording ii (354 mg, 13%) 1H NMR (400 MHz, DMSO-d6) δ 8.90 (s, 1H), 8.26 (d, J=1.8 Hz, 1H), 8.10 (d, J=1.8 Hz, 1H), 5.75 (s, 1H), 5.13 (s, 2H), 4.40 (s, 2H), 3.63 (qq, J=9.6, 7.1 Hz, 4H), 3.38 (q, J=7.1 Hz, 2H), 2.55 (s, 3H), 1.18 (t, J=7.1 Hz, 6H), 1.13 (t, J=7.1 Hz, 3H).

Provenance & Evidence