Reaktion #1729

Reaktionsgleichung

3-hexyl-5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl-carboxylic acid

benzyl 6-hydroxy-nicotinate

dicyclohexylcarbodiimide

→

benzyl 6-(3-hexyl-5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl-carbonyloxy)-nicotinate

Ausbeute 57.0%

Lösungsmittel

methylene chloride

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONpoured into ice-cold aqueous ammonium chloride solution
2. 2
   Extraktionextracted several times with ether
3. 3
   Waschenwashed with water
4. 4
   Trocknendried over sodium sulfate
5. 5
   Sonstigeevaporated
6. 6
   FiltrationThe crude product, for the most part crystalline, was filtered over silica gel (eluent hexane/ethyl acetate=9:1)
7. 7
   Sonstigerecrystallized from hexane
8. 8
   Sonstigecrystallization of the mother liquor

Vorschrift

6 g of 3-hexyl-5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl-carboxylic acid were dissolved in 180 ml of methylene chloride. After the addition of a solution of 4.8 g of benzyl 6-hydroxy-nicotinate in 160 ml of methylene chloride and of 2.3 g of 4-dimethylaminopyridine, the solution was cooled to 0° C. and treated with 4.4 g of dicyclohexylcarbodiimide. The reaction mixture was stirred at 0° C. for 1 hour and at room temperature for 2 hours, thereafter poured into ice-cold aqueous ammonium chloride solution, extracted several times with ether, washed with water, dried over sodium sulfate and evaporated. The crude product, for the most part crystalline, was filtered over silica gel (eluent hexane/ethyl acetate=9:1) and recrystallized from hexane. After repeated crystallization of the mother liquor there were obtained all together 5.7 g of benzyl 6-(3-hexyl-5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl-carbonyloxy)-nicotinate in colorless crystals, m.p. 94°-95° C.

Quelle