Merck Index : 13th edition

Monograph Number: 2413 Title: Clonazepam CAS Registry Number: 1622-61-3 CAS Name: 5-(2-Chlorophenyl)-1,3-dihydro-7-nitro-2H-1,4-benzodiazepin-2-one Additional Names: 7-nitro-5-(2-chlorophenyl)-3H-1,4-benzodiazepin-2(1H)-one Manufacturers' Codes: Ro-5-4023 Trademarks: Clonopin (Roche); Iktorivil (Roche); Klonopin (Roche); Landsen (Sumitomo); Rivotril (Roche) Molecular Formula: C15H10ClN3O3 Molecular Weight: 315.72.
Percent Composition: C 57.06%, H 3.19%, Cl 11.23%, N 13.31%, O 15.20% Literature References: Antiepileptic agent with anxiolytic and antimanic properties. Prepn: L. H. Sternbach et al., J. Med. Chem. 6, 261 (1963); O. Keller et al., US 3121076 (1964 to Hoffmann-La Roche). Prepd but not claimed: J. Kariss, H. L. Newmark, US 3116203 (1963 to Hoffmann-La Roche). Alternate process: A. Focella, A. I. Rachlin, US 3335181 (1967 to Hoffmann-La Roche). Pharmacology: Guerrero-Figueroa et al., Curr. Ther. Res. Clin. Exp. 11, 40 (1969); Lechat et al., Therapie 25, 893 (1970); D'Armagnac et al., ibid. 26, 439 (1971). Toxicology: Blum et al., Arzneimittel-Forsch. 23, 377 (1973). Determn of clonazepam and its main metabolites: S. Ebel, H. Schütz, ibid. 27, 325 (1977). Clinical efficacy in acute mania: G. Chouinard, Psychosomatics 26(12), Suppl., 7 (1985); in panic disorders and agitation: R. Fontaine, ibid. 13. Comprehensive description: W. C. Winslow, Anal. Profiles Drug Subs. 6, 61-81 (1977). Properties: White crystals from ethanol-methylene chloride, mp 236.5-238.5°. uv max (7.5% methanol in isopropanol): 248, 310 nm (e 14500, 11600). Soly in mg/ml at 25°: acetone 31; chloroform 15; methanol 8.6; ether 0.7; benzene 0.5; water <0.1. pK1 1.5, pK2 10.5. LD50 orally in mice: >4000 mg/kg (Blum). Melting point: mp 236.5-238.5° pKa: pK1 1.5, pK2 10.5 Absorption maximum: uv max (7.5% methanol in isopropanol): 248, 310 nm (e 14500, 11600) Toxicity data: LD50 orally in mice: >4000 mg/kg (Blum) NOTE: This is a controlled substance (depressant): 21 CFR, 1308.14. Therap-Cat: Anticonvulsant.