ChemicalBook CAS DataBase List PAPAVERINE HYDROCHLORIDE

PAPAVERINE HYDROCHLORIDE synthesis

8synthesis methods

Product Name:PAPAVERINE HYDROCHLORIDE
CAS Number:58-74-2
Molecular formula:C20H21NO4
Molecular Weight:339.39

Papaverine, 1-veratryl-6,7-dimethoxyisoquinolin (19.4.7), is synthesized from veratrol. Veratrol undergoes chloromethylation, forming 3,4-dimethoxybenzylchloride (19.4.1). Reacting this with potassium cyanide gives 3,4-dimethoxybenzylcyanide (19.4.2). The resulting 3,4-dimethoxybenzylcyanide undergoes reduction by hydrogen over Raney nickel, forming homoveratrylamine (19.4.3). At the same time 3,4-dimethoxybenzylcyanide (19.4.2) undergoes acidic hydrolysis giving 3,4-dimethoxyphenylacetic acid (19.4.4). The interaction of the resulting compounds brings to corresponding amide (19.4.5). The cyclization of this by Bischler–Napieralski method, using phosphorous oxychloride, gives 3,4-dihydropapaverine (19.4.6), which is dehydrated into the desired papverine when heated in tetraline at high temperatures.