| 摘要 |
NEW MATERIAL:A compound of formula I (X1, X2 are halogen; R1 is H, alkyl; R2, R3 are aryl, alkyl, halogenoalkyl). EXAMPLE:9,10-Difluoro-3-methyl-7-oxo-2, 3-dihydro-7H-pyrid[ 1,2,3-de ][ 1,4 ]-benzoxazin-6-carboxylic acid-B(OCOCH2CH3)2-chelate. USE:A synthetic intermediate of antibacterials. PREPARATION:The reaction of a compound of formula II (R5 is H, alkyl) such as 9,10-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrid[1,2,3-de][1,4] benzoxazine-6- carboxylic ethyl ester with a boric carboxylic anhydricide of formula III (R4 is R2, R3, aryl, alkyl, halogenoalkyl) is carried out at room temperature to 150 deg.C for 1-120min, preferably, using 1-10 times molar amounts of the anhydride. |
