MEM CHLORIDE;1-CHLOROMETHOXY-2-METHOXYETHANE;MEM Chlordie;MEM chloride,94%;2-Methoxyethoxymethy;2-MethoxyethoxymethyL;1-Chloro-2,5-dioxahexane;Roxithromycin side chain;Roxithromycin Impurity 15;METHOXYETHOXYCHLOROMETHANE
2-Methoxyethoxymethyl Chloride is an OH-protecting reagent. 2-Methoxyethoxymethyl Chloride is used in the modification of antibiotics.
Purification Methods
Possible impurities are methoxyethanol (b 124o/atm), HCHO and HCl which can be removed below the boiling point of MEMCl. Purify MEMCl by fractional distillation in a vacuum. If too impure, prepare it from methoxyethanol (152g) and s-trioxane (66g) by bubbling a stream of dry HCl (with stirring) until a clear mixture is obtained. Dilute with pentane (900mL), dry (3hours over 100g MgSO4, at 5o), evaporate and the residue is distilled in a vacuum. It is MOISTURE SENSITIVE and TOXIC. The MEM.NEt3+Cl-salt, prepared by reaction with 1.3 equivalents of Et3N (16hours/25o) and dried in a vacuum, has m 58-61o, and is moisture sensitive. [Corey et al. Tetrahedron Lett 809 1976, Yoshimatsu et al. J Org Chem 59 1011 1994, Greene & Wuts Protective Groups in Organic Synthesis edn, J Wiley & Sons NY 1991.] Carcinogen.
