nepinalone nepinalone nepinalone is a cough suppressant. its brand names include placatus, tussolvina, and nepitus. nepinaloneclinical dataatc coder05db26 (who) identifiers iupac name 1-methyl-1-(2-piperidin-1-ylethyl)-3,4-dihydronaphthalen-2(1h)-one cas number22443-11-4pubchem cid3047788chemspider2310106 yuniil9806lpr7gkeggd07396 ychemical and physical dataformulac18h25nomolar mass271.404 g·mol−13d model (jsmol)interactive image smiles o=c2c(c1ccccc1cc2)(ccn3ccccc3)c inchi inchi=1s/c18h25no/c1-18(11-14-19-12-5-2-6-13-19)16-8-4-3-7-15(16)9-10-17(18)20/h3-4,7-8h,2,5-6,9-14h2,1h3 ykey:rvxgrcnwgohsde-uhfffaoysa-n y (verify) the effect is evident after 20–30 minutes after administration and persists for at least 4 hours. it acts primarily at the level of the cns, but also shows a slight activity in inhibiting the bronchospasm. in such use, it is less effective than codeine and more effective than dextromethorphan in inhibiting the tussive stimulus. synthesis orig patent: newer patent: the starting material is called 2-phenylpropanoyl chloride . this is reacted with ethylene in the presence of aluminum trichloride catalyst to give 1-methyl-2-tetralone (1). base catalyzed alkylation of this with 1-(2-chloroethyl)piperidine (2) gives nepinalone (3).