ChemicalBook CAS DataBase List Diltiazem hydrochloride

Diltiazem hydrochloride synthesis

9synthesis methods

Product Name:Diltiazem hydrochloride
CAS Number:33286-22-5
Molecular formula:C22H27ClN2O4S
Molecular Weight:450.98

42399-40-6
66 suppliers
$50.00/2mg

108-24-7
5 suppliers
$14.00/250ML

33286-22-5
510 suppliers
$16.00/250mg

Yield:33286-22-5 92%

Reaction Conditions:

Stage #1: O-desacetyldiltiazem;acetic anhydridewith dmap;triethylamine in dichloromethane; for 3 h;Heating / reflux;
Stage #2: with hydrogenchloride in methanol; pH=2;

Steps:

2.d Preparation of Cis-(+)-3-(Acetyloxy)-2,3-dihydo-5-[2-(dimethylamino)-ethyl]-2-(4-methoxyphenyl)-1,5-benzothiazepin-4(5H)-one Hydrochloride (Diltiazem Hydrochloride)

The N-alkylated lactam (0.317 mmol), Ac2O (1 mmol), Et3N (2 mmol) and DMAP (0.03 mmol) taken in CH2Cl2 (5 mL) were heated at reflux under N2 for 3 h. The mixture was poured into ice water and brine was added. The organic layer was separated and the aqueous layer was extracted with CH2Cl2 (10 mL). The combined organic layers were washed with 5% NH4OH (5 mL) solution, dried (Na2SO4) and evaporated. The residue was dissolved in MeOH (2 mL) and treated with anhydrous HCl gas till pH was 2. Ether (3 mL) was added to the resulting solution. The precipitated solids were collected by filtration and washed with 10% MeOH-ether to afford diltiazem hydrochloride (92% yield).

References:

WO2004/58734,2004,A1 Location in patent:Page 7-8

75472-91-2 Synthesis