| 摘要 |
<p>In the prepn. of a cpd. of formula (I) (R, R1 = H, 1-4C alkyl, F or Cl; R2, R3 = H or 1-6C alkyl) which includes catalytically hydrogenating a cpd. of formula (II), the reaction is carried out in an acid medium stronger than glacial acetic acid, pref. trifluoroacetic acid or hydrochloric acid. - The process is pref. carried out in the presence of hydrogenation catalyst at 1-4 atmos. H2 and 20-70 deg.C.</p> |
