| 摘要 |
<p>Title cpds. have formula (R1,R2 = H, C1-12 alkyl, C2-12 alkenyl, C5-12 cycloalkyl, C7-12 aralkyl or aryl; X = halogen) are starters for dyes and pesticides. Prepn. from the corresp. 2,3-dihalo-cpds. with mercaptans and a base (org. or inorg) in inert org. solvents gives good yields of pure 2-halo-cpds. practically without-3-halo isomers. In an example 173 parts (71%) 2-chloro-3-phenyl-mercapto-maleic aldehyde-acid, m.pt. 160-162 degrees are obtd. from 169 parts mucochloric acid and 110 parts thiophenol with 59 parts isorpopylamine in acetone.</p> |
