303-53-7

Cyclobenzaprine is structurally similar to tricyclic antidepressants. It acts at the brain stem level.

Flexeril,Merck Sharp andDohme,US,1977

It is used as an adjuvant agent for relieving muscle spasms associated with severe diseased conditions of the muscle. A synonym of this drug is flexeril.

Relaxant (muscle).

ChEBI: 5-Methylidene-5H-dibenzo[a,d]cycloheptene in which one of the hydrogens of the methylidene group is substituted by a 2-(dimethylamino)ethyl group. A centrally acting skeletal muscle relaxant, it is used as its h drochloride salt in the symptomatic treatment of painful muscle spasm.

In an initial step, dibenzo [a,d]cyclohepten-5-one is reacted with the Grignardreagent of 3-dimethylaminopropyl chloride and hydrolyzed to give 5-(3-dimethylaminopropyl)-dibenzo[a,d][1,4]cycloheptatriene-5-ol. Then 13 g ofthat material, 40 ml of hydrochloric acid, and 135 ml of glacial acetic acid isrefluxed for 3? hours. The solution is then evaporated to dryness in vacuoand added to ice water which is then rendered basic by addition of ammoniumhydroxide solution. Extraction of the basic solution with chloroform andremoval of the solvent from the dried chloroform extracts yields the crudeproduct which when distilled in vacuo yields essentially pure 5-(3-dimethylaminopropylidene)-dibenzo[a,d][1,4]cycloheptatriene, BP 173°C to177°C at 1.0 mm.

Flexeril (McNeil).

Muscle relaxant

Cyclobenzaprine, N,N-dimethyl-3-(dibenzo[a,d]cyclohepten-5-ylidene) propylamine (15.3.9), is synthesized by reacting 5H-dibenzo[a,d]cyclohepten-5-one with 3-dimethylaminopropylmagnesium chloride and subsequent dehydration of the resulting carbinol (15.3.8) in acidic conditions into cyclobenzaprine (15.3.9).