Sodium Bicarbonate → Letermovir

Participants

Reaction Steps

(2S,3S)-2,3-Bis[(4-methylbenzoyl)oxy]succinic acid-methyl {8-fluoro-2-[4-(3-methoxyphenyl)-piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-3,4-dihydroquinazolin-4-yl}acetate (1:1 salt) (10.1 g, containing 14 ppm of Pd) are suspended in ethyl acetate (100 ml) and shaken with saturated aqueous sodium bicarbonate solution (100 ml) until both phases are clear. The phases are separated and the organic phase is concentrated in a rotary evaporator. The residue is dissolved in 1,4-dioxane (100 ml) and 1N sodium hydroxide solution (31.2 ml) and stirred at room temperature for 3 h. Subsequently, the pH is adjusted to 7.5 using 1N hydrochloric acid (ca. 17 ml), MIBK (80 ml) is added, then the pH is readjusted to 7.0 using 1N hydrochloric acid (ca. 2 ml). The phases are separated, and the organic phase is dried over sodium sulphate and concentrated. The residue is dissolved in ethanol (40 ml) and concentrated, then dissolved in ethanol (40 ml) again and concentrated and dried at 50° C. in a high vacuum. The solidified foam is dried at 45° C. for 18 h in the VDO using entraining nitrogen. A total of 5.05 g of (S)-{8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-(2-methoxy-5-trifluoromethylphenyl)-3,4-dihydroquinazolin-4-yl}acetic acid are obtained as an amorphous solid, corresponding to 85.0% of theory.

Provenance & Evidence