反応 #61359

反応方程式

Compound 20a

N-Boc-(1R,2S)-1-amino-2-vinylcyclopropane carboxylic acid methyl ester

HCl

MeOH

→

compound 20b

収率 76.0%

(1R,2S)-1-amino-2-vinylcyclopropane carboxylic acid methyl ester hydrochloride

収率 76.0%

溶媒

dioxane

dioxane

反応条件

後処理

1. 1
   workup.ADDITIONthe solution added dropwise
2. 2
   その他Volatiles were removed under reduced pressure
3. 3
   workup.ADDITIONEther (300 mL) and MeOH (10 mL) were added to the brown, oily residue
4. 4
   その他resulting in the precipitation of a semi-solid
5. 5
   workup.STIRRINGstirring
6. 6
   workup.WAITcontinued for 6 h, at which point
7. 7
   ろ過a yellowish solid was collected by filtration
8. 8
   洗浄The product was washed with 5% MeOH in ether (50 mL) and ether (2×50 mL)
9. 9
   その他dried in vacuo

実験手順

Compound 20a (39.96 g, 165.7 mmol) was dissolved in dioxane (25 mL) and the solution added dropwise with stirring to 4 N HCl in dioxane (Aldrich, 250 mL). After 45 min, TLC analysis indicated complete deprotection. Volatiles were removed under reduced pressure, and the residue co-evaporated twice with MeOH (2×100 mL). Ether (300 mL) and MeOH (10 mL) were added to the brown, oily residue and the mixture stirred overnight at room temperature resulting in the precipitation of a semi-solid. Additional MeOH (15 mL) was added and stirring continued for 6 h, at which point a yellowish solid was collected by filtration. The product was washed with 5% MeOH in ether (50 mL) and ether (2×50 mL), and dried in vacuo to give compound 20b as a yellowish solid (22.60 g, 76% yield). Filtrates (including washings) were evaporated in vacuum to give additional 20b as a brown oil (7.82 g, 26% yield). Both fractions were pure enough for use in the synthesis of HCV protease inhibitors: [a]D25+38.2° (c 1.0, MeOH).

出典