反应详情

At 0° C., 12.9 g of γ-ethoxy-γ-butyrolactam, 10 ml of conc. sulphuric acid and 90 ml of glacial acetic acid were initially charged and admixed, a little at a time, with a total of 18.8 g of phenol. After thawing, the mixture was stirred at room temperature for 2 days. For work-up, the mixture was poured onto ice and extracted three times with ethyl acetate, and the combined extracts were washed once each with water and saturated sodium chloride solution, dried and concentrated. After some time, γ-2-hydroxyphenyl-γ-butyrolactam (XI-2b) of melting point 220° C. (6.4 g, 36% of theory) crystallized from the aqueous phase. The residue obtained after concentration was stirred with a 1:1 mixture of cyclohexane/ethyl acetate and gave, after filtration with suction, 4.65 g of γ-4-hydroxyphenyl-γ-butyrolactam (XI-2a) of melting point 183° C. The filtrate was concentrated. A further 3.35 g (total: 45% of theory) of γ-4-hydroxyphenyl-γ-butyrolactam were obtained by recrystallization from dichloromethane/hexane.

1. additionFor work-up, the mixture was poured onto ice
2. extractionextracted three times with ethyl acetate
3. washthe combined extracts were washed once each with water and saturated sodium chloride solution
4. customdried
5. concentrationconcentrated
6. customAfter some time, γ-2-hydroxyphenyl-γ-butyrolactam (XI-2b) of melting point 220° C. (6.4 g, 36% of theory) crystallized from the aqueous phase
7. customThe residue obtained
8. concentrationafter concentration
9. stirringwas stirred with a 1:1 mixture of cyclohexane/ethyl acetate
10. customgave
11. filtrationafter filtration with suction, 4.65 g of γ-4-hydroxyphenyl-γ-butyrolactam (XI-2a) of melting point 183° C
12. concentrationThe filtrate was concentrated