反应详情

A mixture of 1 g of L-cysteic acid, 8 ml of 4 N hydrochloric acid in dioxane and 30 ml dry methanol was placed in a bottle. The bottle was capped and stored for approximately 96 hours at room temperature. Thin layer chromatography of the clear solution [Analtech silica gel plates, n-butanol:ethyl acetate:acetic acid:water (1:1:1:1), chlorine/potassium iodide-starch reagent (Stewart J. M. and Young J. D. in Solid Phase Peptide Synthesis, Pierce Chemical Company, PP.120 (1984)] indicated greater than 95 % conversion of cysteic acid to the ester. Solvents were removed under vacuum to get 1.05 g of a sticky solid. Mass spec analysis gave the m/z for the major M+1 ion as 184.3. Fragmentation of this ion gave the M+1 ion of 123.9, which represents the loss of one of the carboxymethyl groups. The solids were used without further purification in the next step.

1. customThe bottle was capped
2. customSolvents were removed under vacuum