Реакция #65615

Уравнение реакции

(2S,4S)-4-(4-methoxybenzylthio)-2-pyrrolidinecarboxylic acid

sodium hydroxide

4-nitrobenzyloxycarbonyl chloride

sodium hydroxide

→

title compound

Выход 77.5%

(2S,4S)-4-(4-Methoxybenzylthio)-1-(4-nitrobenzyloxycarbonyl)-2-pyrrolidinecarboxylic acid

Выход 77.5%

Растворители

water

tetrahydrofuran

tetrahydrofuran

Условия реакции

Обработка

1. 1
   workup.ADDITIONwere gradually added dropwise at the same time
2. 2
   workup.STIRRINGthe resulting mixture was stirred under the same conditions for 10 minutes
3. 3
   ДругоеAt the end of this time, the tetrahydrofuran was removed by evaporation under reduced pressure
4. 4
   workup.ADDITION1N aqueous hydrochloric acid was added to the reaction solution
5. 5
   ДругоеThe crystals which separated
6. 6
   Фильтрацияwere collected by filtration
7. 7
   Промывкаwashed well with water
8. 8
   Другоеdried in the air
9. 9
   ПромывкаThey were then further washed with a small amount of diethyl ether
10. 10
    Другоеdried

Методика

1.87 g of (2S,4S)-4-(4-methoxybenzylthio)-2-pyrrolidinecarboxylic acid [prepared as described in step (a) above] was suspended in 80 ml of a 1:1 by volume mixture of tetrahydrofuran and water. This suspension was then converted to a homogeneous solution by the addition of 7 ml of a 1N aqueous solution of sodium hydroxide. Whilst stirring this solution on an ice bath, 10 ml of a tetrahydrofuran solution containing 1510 mg of 4-nitrobenzyloxycarbonyl chloride and 7 ml of a 1N aqueous solution of sodium hydroxide were gradually added dropwise at the same time, and the resulting mixture was stirred under the same conditions for 10 minutes. At the end of this time, the tetrahydrofuran was removed by evaporation under reduced pressure. 1N aqueous hydrochloric acid was added to the reaction solution to adjust its pH to a value of between 2 and 3. The crystals which separated were collected by filtration, washed well with water and dried in the air. They were then further washed with a small amount of diethyl ether and dried, to obtain 2.42 g of the title compound, melting at 96°-98° C.

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