[CH3:1][O:2][CH2:3][C:4]1[O:8][N:7]=[C:6]([NH2:9])[CH:5]=1.[OH:10][C:11]1[C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=2[S:14](=[O:22])(=[O:21])[N:13]([CH3:23])[C:12]=1[C:24](OC)=[O:25]>C1(C)C(C)=CC=CC=1>[OH:10][C:11]1[C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=2[S:14](=[O:22])(=[O:21])[N:13]([CH3:23])[C:12]=1[C:24]([NH:9][C:6]1[CH:5]=[C:4]([CH2:3][O:2][CH3:1])[O:8][N:7]=1)=[O:25]A mixture of 0.52 g (4 mmole) of 5-(methoxymethyl)-3-isoxazolamine, 1.08 g (4 mmole) of methyl 4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide, and 100 ml of xylene is heated at reflux for six hours in a soxhlet apparatus, the thimble of which contains 20 g of Linde type 4A molecular sieve. The reaction mixture is filtered to clarify it and is allowed to stand at room temperature overnight when the product crystallizes out. The product is filtered, washed with methanol-ether mixture, and then recrystallized from methanol to give 0.326 g of white crystals, mp 218°-223° C. dec.
불러오는 중…