Lopirazepam, D-12524

氯吡西泮Chemical Name: 7-Chloro-5-(2-chlorophenyl)-3-hydroxy-2,3-dihydro-1H-pyrido[3,2-e][1,4]diazepin-2-one
CAS No. 42863-81-0, 42785-35-3 (Na salt)
项目整合开发状态: Not Determined
项目研究机构:
合成路线:The reaction of 2,6-dichloro-3-nitropyridine (I) with 2-chlorobenzyl cyanide (II) by means of NaH in dioxane gives 2-(2-chloro-alpha-cyanobenzyl)-3-nitro-6-chloropyridine (III),which is oxidized with H2O2 and KOH in acetone yielding 2-(2-chlorobenzoyl)-3-nitro-6-chloropyridine (IV).The reduction of (IV) with H2 over Raney-Ni in dioxane affords 2-benzoyl-3-amino-6-chloropyridine (V),which is converted into 2-(2-chlorobenzoyloximino)-3-amino-6-chloropyridine (VI).The condensation of (VI) with chloroacetyl chloride (A) by means of HCl in HOAc gives 2-(2-chlorobenzoyloximino)-3-chloroacetylamino-6-chloropyridine (VII),which is cyclized by means of KOH in ethanol affording 5-(2-chlorophenyl)-7-chloro-6-aza-1,3-dihydro-2H-1,4-benzodiazepin-2-one-4-oxide (VIII) with refluxing acetic anhydride yields 1-acetyl-3-acetoxy-5-(2-chlorophenyl)-7-chloro-6-aza-1,3-dihydro-2H-1,4-benzodiazepin-2-one (IX).Finally this compound is deacetylated by treatment with KOH in ethanol at room temperature.