[OH:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8](=[O:10])[S:7][C:6]=2[CH:11]=1.[C:12]([O:16][CH2:17][CH2:18][N:19]=[C:20]=[O:21])(=[O:15])[CH2:13][CH3:14]>C([O-])(=O)CCCCCCCCCCC.C([O-])(=O)CCCCCCCCCCC.C([Sn+2]CCCC)CCC.C(C(C)=O)C>[C:12]([O:16][CH2:17][CH2:18][NH:19][C:20]([O:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8](=[O:10])[S:7][C:6]=2[CH:11]=1)=[O:21])(=[O:15])[CH2:13][CH3:14]5-hydroxy-1,3-benzoxathiol-2-one (16.8 grams) was mixed with 2-(isocyanato)ethyl propionate (15.0 grams) and 10 drops of dibutyltin dilaurate in 200 milliliters of methyl ethyl ketone. The resulting solution was heated at reflux temperature for four hours and fifteen minutes, after which the solvent was removed by evaporation in vacuo, leaving a brown, viscous oil which crystallized upon standing at room temperature for 10 to 15 hours. The crude product was twice recrystallized from toluene. The purified compound, 5-[2-(propionyloxy)ethylcarbamoyloxy]-1,3-benzoxathiol-2-one, was a white, fibrous crystalline substance with a melting point of 78°-79° C. Elemental analysis calculated for C13H13NO6S (percent): carbon--50.15; hydrogen--4.21; nitrogen--4.50. Found: carbon--50.4; hydrogen--4.27; nitrogen--4.45.
Wird geladen…
