反应详情

N-(tert-Butoxycarbonyl)-ethylthio-L-cysteine methyl ester 15 (106 mg, 0.40 mmol) was added to a 50 mL round bottom flask and dissolved in DMF (5 mL). Potassium carbonate (278 mg, 2.01 mmol) was added by pipette as a solution in water (1.0 mL). MSH 1 (172 mg 0.80 mmol) was added as a solid in one portion (open air, room temperature). TLC analysis (ethyl acetate:petrol; 1:4) after 1 min of reaction revealed a strongly UV active product (Rf 0.6) and a trace of starting material (Rf 0.5). A second dose of MSH 1 (172 mg 0.80 mmol) was added after 5 min of reaction time and TLC analysis revealed only the UV active product. After 10 min of total reaction time, the reaction mixture was diluted with diethyl ether (100 mL) and water (50 mL). The organic layer was separated and the aqueous layer was extracted with diethyl ether (2×50 mL). The combined organics were dried (MgSO4), filtered, and the solvent removed by rotary evaporation. Column chromatography (3% ethyl acetate in petrol) provided methyl 2-[(tert-butoxycarbonyl)amino]acrylate 3 (63 mg, 79%); this material was spectroscopically identical to that obtained from N-(tert-butoxycarbonyl)-L-cysteine methyl ester 2.

1. additionMSH 1 (172 mg 0.80 mmol) was added as a solid in one portion (open air, room temperature)
2. additionA second dose of MSH 1 (172 mg 0.80 mmol) was added after 5 min of reaction time and TLC analysis
3. customThe organic layer was separated
4. extractionthe aqueous layer was extracted with diethyl ether (2×50 mL)
5. dry with materialThe combined organics were dried (MgSO4)
6. filtrationfiltered
7. customthe solvent removed by rotary evaporation