Originator
Ajan,Kettelhack Riker,W. Germany,1976
Uses
Nefopam is a non-opioid non-steroidal centrally acting analgesic.
Definition
ChEBI: 5-methyl-1-phenyl-3,4,5,6-tetrahydro-1H-2,5-benzoxazocine is a member of the class of benzoxazocines that is 3,4,5,6-tetrahydro-1H-2,5-benzoxazocine substituted by phenyl and methyl groups at positions 1 and 5 respectively. It is a benzoxazocine and a tertiary amino compound.
Manufacturing Process
The starting material is prepared by reacting 2-benzoylbenzoic acid with
thionyl chloride and then with 2-methylaminoethanol. 20.0 grams (0.07 mol)
of N-(2-hydroxyethyl)-N-methyl-o-benzoylbenzamide is suspended in 100 ml
tetrahydrofuran and then slowly added in small portions to a solution of 5.5
grams (0.14 mol) of lithium aluminum hydride in 150 ml tetrahydrofuran with
cooling and stirring. The mixture is then refluxed for 18 hours, cooled and
then to it is successively added 5.5 ml water, 5.5 ml of 3.75 N sodium
hydroxide and 16 ml water. After removal of precipitated salts by filtration, the
solution remaining is concentrated under reduced pressure and the residue
dried to yield 19.5 grams of crude product. Yield after conversion to the
hydrochloride salt and recrystallization is 17.0 grams (89%), MP 128° to
133°C.
5-methyl-1-phenyl-1,3,4,6-tetrahydro-5H-benz[f] -2,5-oxazocine is prepared
as follows. 3.0 grams (0.011 mol) of 2-([N-(2-hydroxyethyl)-Nmethyl]amino)methylbenzhydrol, prepared as described above, 3.0 grams ptoluenesulfonic acid and 15 ml benzene are heated together with stirring until
all the benzene is distilled off. The residual oil is heated to 105°C and held at
this temperature for 1 hour, then cooled and dissolved in 30 ml water. This
aqueous solution is then basified to pH 10.0 with 12 N sodium hydroxide,
extracted with ether, and the extracts washed with water, dried over
anhydrous sodium sulfate and the solvent removed under reduced pressure.
The 2.26 grams (81%) oil remaining is converted to the hydrochloride salt, MP
238° to 242°C.
Brand name
Acupan (3M
Pharmaceuticals).
Therapeutic Function
Muscle relaxant, Antidepressant
Clinical Use
Nefopam is a centrally
acting analgesic without opioid properties. It induces
inhibition of NA and 5-HT reuptake and
has antimuscarinic and sympatomimetic actions
which all might be relevant for its analgesic action.
Nefopam is used orally and parenterally for
the treatment of moderately severe pain. Side
effects are nausea, vomiting, sweating, nervousness,
tachycardia, and occasionally convulsions.
Nefopam should not be used in combination
with MAO inhibitors.
