Hydrogen Bromide → Citalopram Hydrobromide

Participants

Reaction Steps

To a solution of 7.1 g of citalopram base in 35 ml of dichloromethane a solution of 7 g of sodium metabisulphite in 25 ml of deionized water is added. The pH of the mixture is brought to 6.0 by addition of 5% aqueous ammonium hydroxide, then the organic phase is discarded, the aqueous one is brought to pH=7.0 by addition of sodium bicarbonate and extacted with 2×10 ml of toluene. The organic extracts are concentrated under vacuum at 50° C. to give 6.9 g of citalopram base with purity (HPLC)=99.8% (area). These 6.9 g of citalopram base are dissolved in 30 ml of acetone and 48% HBr is added to the solution to a pH of 4÷5. The obtained solution is evaporated under vacuum at 45° C. and the residue is crystallized with acetone to give 5.6 g of citalopram hydrobromide with purity HPLC)=99.4% (area) and m.p. 185÷187° C.

Provenance & Evidence