Synthesis
Toluene-4-sulfonic acid 2-[2-(2-methoxyethoxy)-ethoxy]-ethyl ester (2.7) (10.8 g, 34 mmol) and
thiourea (2.6 g, 34 mmol) were dissolved in a mixture of absolute EtOH (20 mL) and H2O (14
mL) and the mixture was refluxed for 3h. 4N NaOH solution (10 mL) was added to mixture and
the reaction mixture refluxed 2 more h. The reaction mixture was concentrated under reduced
pressure to ~ 10 mL, diluted with distilled H2O (10 mL) and neutralized with concentrated HCl.
The solution was extracted with CH2Cl2 (3x10mL) and the solvent was evaporated under
reduced pressure. The pink-yellow liquid was distilled at 0.45 torr pressure. The product was
collected as a clear liquid and obtained in 54% yield. B.p. 55-57 °C at 0.45 torr. GC-MS Calcd.
C7H16O3S+
: 180.0; found: 179.9. 1
H NMR (250 MHz, CDCl3) δ 3.6(6H), 3.5(4H), 3.4(3H),
2.7(2H), 1.6(1H); 13
C NMR (300 MHz, CDCl3) δ 76.92, 73.30, 72.34, 70.98, 70.63, 59.46, 24.66
