反应详情

30 g of 6-hydroxynicotinic acid were treated with 500 ml of benzyl alcohol and 1 ml of concentrated sulfuric acid. After boiling at reflux for 3 days, the reaction mixture was poured on to ice-water, extracted several times with ethyl acetate, washed with water, dried over sodium sulfate and evaporated, firstly in a water-jet vacuum and then in a high vacuum. The semi-crystalline residue was filtered over silica gel (eluent hexane/ethyl acetate=2:1, then ethyl acetate) and recrystallized from ethyl acetate/hexane. There were obtained 19 g of benzyl 6-hydroxy-nicotinate in colourless crystals, m.p. 178°-179° C.

1. temperatureat reflux for 3 days
2. extractionextracted several times with ethyl acetate
3. washwashed with water
4. dry with materialdried over sodium sulfate
5. customevaporated, firstly in a water-jet vacuum
6. filtrationThe semi-crystalline residue was filtered over silica gel (eluent hexane/ethyl acetate=2:1
7. customethyl acetate) and recrystallized from ethyl acetate/hexane