Isopropanol → Urea, (4-methoxyphenyl)-

Participants

Reaction Steps

P1-(cytidine 5′-)-P4-(uridine 5′-)tetraphosphate, ditributylammonium salt (50 mg, 0.043 mmol; prepared from the tetraammonium salt by treatment with Dowex 50W×4H+ in water, followed by mixing the protonated species with an excess of tributylamine in methanol, stripping and lyophilization) was dissolved in dry DMF (1 mL) and tributylamine (10 uL, 0.43 mmol), and p-methoxyphenylisocyanate (8.4 uL, 0.648 mmol) were added in a single portion. The homogeneous reaction mixture was heated overnight at 35° C., whereupon TLC (silica gel, 50% isopropanol/50% ammonium hydroxide) and HPLC (C18) indicated a substantial conversion to a single product. The solvent was removed on a rotary evaporator and the residue dissolved in water (1 mL). The product was isolated by repeated injections onto a semi-preparative HPLC column (Alltech Nucleotide/Nucleoside C18, 7 um, 10×250 mm, gradient from 0.1 M ammonium acetate to methanol over 30 minutes, 5 mL/min, monitor at 260 nm). Stripping and lyophilization gave the p-methoxyphenylurea (24 mg, 55% yield), as the tetraammonium salt.

Provenance & Evidence