| 摘要 |
<p>Novel prepn. of substd. benzamide derivs. of formula (I) (where A is alkyl or alkenyl; X is Cl or Br; R1 is 2-4C alkylene; and R2 and R3 are alkyl) and their acid addn. salts is claimed. A substd. benzoic acid of formula (II) is reacted with a halo-formic acid ester of the formula X'COOR4 (III) (where X' is halogen and R4 is alkyl or aralkyl) and the resulting mixed anhydride is reacted with an amine of formula H2N-R1-NR2R3 (IV), the product opt. being isolated in the form of an acid addn. salt. The two reactions are carried out in succession as a 'one-pot' process. The cpds. (I) include 4-amino-5-chloro-N-(2-diethylaminoethyl)-2-methoxy-benzamide, a known cpd. with analgesic, anticonvulsant, sedative, anaesthetic and antiemetic activity. (I) are generally obtd. in yields of 90% or more. Prod. purity is high. The process is simple to carry out, and starting materials are readily obtainable. The 4-amino group of (II) does not have to be protected. In an example, 2-methoxy-4-amino-5-chlorobenzoic acid in THF is treated with isobutyl chloroformate in the presence of triethylamine, and diethylaminoethylamine is subsequently added. N-(2-diethylaminoethyl)-2-methoxy-4-amino-5-chlorobenzamide is obtd. in 86.3% yield.</p> |
