File:Roxatidine synthesis.svg|thumb|center|500px|ThiemeChemDrug Synthesis: Patent: Sino revised protocols: The reductive amination between
piperidine (
1) and
3-hydroxybenzaldehyde (
2) gives 3-(1-piperidinylmethyl)phenol (
3).
Williamson ether synthesis with
N-(3-bromopropyl)phthalimide (
4) gives the intermediate
5.
Deprotection with
hydrazine yields (3-(1-piperidinylmethyl)phenoxy)propylamine (
6). Heating with
glycolic acid (
7) provides roxatidine (
8) which is then converted to its acetate ester, roxatidine acetate (
9), by acetylation with
acetic anhydride. == References ==