The reaction of 4-hydroxybenzaldehyde (I) with cyanacetic acid (II) by means of pyridine in toluene gives the 3-(4-hydroxyphenyl)propenenitrile (III), which by reaction first with methanolic HCl and then with methanolic ammonia is converted into the amidine (IV). Finally, this compound is condensed with 2-furylcarbonyl chloride (V) in pyridine and treated with methanesulfonic acid to afford the target sulfonate.
The acylation of (E)-3-(4-hydroxyphenyl)-2-propenamide (VI) with acetic anhydride gives the 4[(E)-3-amino-3-oxo-1-propenyl]phenyl acetate (VII), which by reaction first with BF3 ethearate and then with ammonia is converted into the amidine (IV). Finally, this compound is condensed with 2-furylcarbonyl chloride (V) in pyridine and treated with methanesulfonic acid to afford the target sulfonate.