| 摘要 |
Cpds. (I) R1 = H, lower alkyl (straight or branched), phenyl or benzyl Hal=Cl or Br n and m are 0 and 0, 0 and 1 or 1 and 0 1-Cyano-1-isopropyl-4-bromo-5,6-dimethoxytetralin; 1-cyano-3-bromo-6,7-dimethoxytetralin; 1-cyano-1-isopropyl-4-bromo-6,7-dimethoxytetralin; 1-(3',4'-Dimethoxyphenyl)-2-methylbutyronitrile is alkylated by the diethyl acetal of bromoacetaldehyde. The product (167.5 g.) + HBr (bubbled in) + toluene (500 ml) at 5-15 deg.C for 2 hrs. About 100g. of HBr is absorbed. Then mixed for 3 hrs. at 20 deg.C, and left for 12 hrs. at 5 deg.C. Solvent distilled off by vacuum-distillation at 30 deg.C. Residue dissolved in 250 ml. of ethyl acetate and cooled. Filtered; ppt. recrystallized from ethyl acetate: 75 g. (46% yield) of 1-cyano-1-isopropyl-3-bromo-5,6-dimethoxyindane (m.p. 107-108 deg.C) (a cpd. I). |
