Triethylene glycol monomethyl ether → HCID 69921530, compound

Participants

Reaction Conditions

Reaction Steps

3 was prepared by transesterification of 1 with triethyleneglycol monomethyl ether following the procedure reported by Muñoz-Guerra et al.21 A vigorously stirred solution of 1 (2.05 g, 10 mmol) and titanium(IV) tetrabutoxide (0.1 g, 0.3 mmol) in dry tri(ethylene glycol) monomethyl ether (20 mL) was heated at 90° C. for 12 h. The course of transesterification was followed by TLC. The reaction was assumed to be complete when no trace of UV absorption indicative of 1 was detectable. The unreacted tri(ethylene glycol) monomethyl ether was distilled off under vacuum and can be reused. The remaining brown residue was purified by passage through a silica gel column (ethyl acetate and hexane, 1:1). The eluent fractions containing product were combined and the solvent was evaporated under vacuum to afford a light yellow oil. Pure compound 3 was obtained by vacuum distillation of this oil (1.21 g, 46%). FTIR (THF): 1779 cm−1 (νCO, lactam, s), 1745 cm−1 (νCO, ester, s). 1H NMR (CDCl3, 500 MHz) δ 6.73 (br, 1H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 4.36 (m, 2H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 4.19 (dd, 1H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 3.71 (m, 2H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 3.63 (m, 6H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 3.54 (m, 2H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 3.37 (s, 3H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 3.26 (ddd, 1H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)), 3.08 (ddd, 1H, CH—2C(O)NHCH(CO2CH2CH2OCH2CH2OCH2CH2OCH3)). 13C NMR (CDCl3, 200 MHz) δ 171.4, 166.4, 72.2, 71.0, 70.9, 70.8, 69.1, 64.9, 59.3, 47.6, 43.9. [α]25D: −15.1 (C 0.52 in THF) MS calcd: 261.28; found: 262.33 (MH+).

Provenance & Evidence