Process for the preparation of dihydroquinazolines
View Patent ↗The present invention relates to a process for the preparation of dihydroquinazolines, for example, methyl (S)-{8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoro -methyl)-phenyl]-3,4-dihydroquinazolin-4-yl}acetate (2S,3S)-2,3-bis[(4-methylbenzoyl) -oxy]succinic acid salt, which are used for the production of antiviral medicaments.
1. A process for isolating methyl (S)-{8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-3,4-dihydroquinazolin-4-yl}acetate (2S,3S)-2,3-bis[(4-methylbenzoyl)-oxy]succinic acid salt, comprising crystallizing racemic methyl -{8-fluoro -2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-3,4-dihydroquinazolin-4-yl}acetate with (2S,3S)-2,3-bis[(4-methylbenzoyl)oxy]succinic acid.
2. Methyl (S)-{8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy -5-(trifluoro-methyl)-phenyl]-3 ,4-dihydroquinazolin-4-yl}acetate (2S,3S)-2,3-bis[(4-methylbenzoyl)-oxy]succinic acid salt.