2-Butanol, 4-(dimethylamino)-3-methyl-1,2-diphenyl-, propionate (ester), 2-naphthalenesulfonate (salt), (-)- 2-Naphthalenesulfonic acid, compd. with (1R,2S)-3-(dimethylamino)-2-methyl-1-phenyl-1-(phenylmethyl)propyl propanoate (1:1) 5667-69-6 5714-90-9 Benzeneethanol, alpha-(2-(dimethylamino)-1-methylethyl)-alpha-phenyl-, propanoate (ester), (R-(R*,S*))-, 2-naphthalenesulfonate (salt) EINECS 227-209-1 Letusin Levopropoxyphen napsylate Levopropoxyphene napsilate Levopropoxyphene napsylate anhydrous Levoproxyphene 2-naphthalenesulfonate Novrad Regretos