J. Org. Chem. 1981,46, 4658-4662
4658
and the reaction stirred further for 9 days. The disappearance of IR peaks a t 2130 and 1820 cm-’ was used as evidence for complete reaction. Mter removal of dicyclohexylurea by filtration, the solvent and excess thiol were removed by rotary evaporation. EbO (35 mL) was added and the solution washed sequentially with NaHC03, with 1 M HzS04,and again with saturated NaHCOS. After drying and rotary evaporation, the thioester product was vacuum distilled as reported above. GC analysis showed that the crude product (85% yield) contain 19% N-acylurea and