| abstract |
1, 4-Benzodiazepine-2-one tranquilisers, pref. of formula (I): (where R1 H or 1. alkyl esp. Me; R2 and R3=H or hal esp H;R4=H, hal or NO2, esp. Cl, and R5=H or OH, esp H). are purified by reaction with R6SO3H, where R6=alkyl or aryl, pref. Me Ph or p-Me. C6H4, to give the salt After recrystallisation, the purified salt is decompsd. with base, extd, and recrystallised. |