Реакция #1729

Уравнение реакции

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

Выход 57.0%

Растворители

methylene chloride

methylene chloride

Условия реакции

Обработка

1. 1
   workup.ADDITIONpoured into ice-cold aqueous ammonium chloride solution
2. 2
   Экстракцияextracted several times with ether
3. 3
   Промывкаwashed with water
4. 4
   Сушкаdried over sodium sulfate
5. 5
   Другоеevaporated
6. 6
   ФильтрацияThe crude product, for the most part crystalline, was filtered over silica gel (eluent hexane/ethyl acetate=9:1)
7. 7
   Другоеrecrystallized from hexane
8. 8
   Другоеcrystallization of the mother liquor

Методика

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.

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