Clocinizine is a first-generation antihistamine of the diphenylmethylpiperazine class. It is marketed in Spain in combination with phenylpropanolamine under the brand name Senioral.[1]

Synthesis

Synthesis:[2] Patent:[3]

The reduction of 4-Chlorobenzophenone [134-85-0] (1) with NBH gives 4-Chlorobenzhydrol [119-56-2] (2). Halogenation of the alcohol in muriatic acid afforded 4-Chlorobenzhydryl chloride [134-83-8] (3). Alkylation with one equivalent of piperazine gives 1-(4-Chlorobenzhydryl)piperazine [303-26-4] (4). Alkylation of the remaining nitrogen with Cinnamyl Bromide [4392-24-9] (5) completed the synthesis of Clocinizine (6).

References

  1. ^ Fookes C (September 2022). "List of Common Antihistamines + Uses & Side Effects". Drugs.com.
  2. ^ Venkat Narsaiah A, Narsimha P (April 2012). "Efficient synthesis of antihistamines clocinizine and chlorcyclizine". Medicinal Chemistry Research. 21 (4): 538–541. doi:10.1007/s00044-011-9556-x. S2CID 253636495.
  3. ^ DE 2220242, Kato H, Kurata S, "Antiarrhythmic piperazine derivs prepn - from benzhydrylpiperazine cinnamaldehyde by leuckart reaction", issued 1972, assigned to Hokuriku Pharmaceutical