Potassium Hydroxide → 3-bromo-6,7,8,9-tetrahydro-5H-10-thia-7-aza-benzo[a]azulene

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Reaction Steps

30.0 g (53.5 mmol) KOH in 700 mL EtOH are added to a solution of 19.0 g (53.5 mmol) ethyl 3-bromo-5,6,8,9-tetrahydro-10-thia-7-aza-benzo[a]azulen-7-carboxylate. EtOH is distilled off at normal pressure and the residue is taken up in water. The solution is acidified with HCl. Then it is made basic with NaOH and the aqueous phase is extracted four times with chloroform. The organic phase is dried over Na2SO4 and K2CO3 and the solvent is eliminated i.vac. The purification is carried out by repeated column chromatography on silica gel.

Provenance & Evidence