反应详情

Concentrated HCl (1l) was added with 40% w/v formaldehyde (65 ml, 0.86 mole) under vigorous stirring, then with 3-methoxybenzoic acid (100 g, 0.66 mole) and the mixture was heated to 100° C. controlling the generation of gas, for 30 minutes. The cooling of the mixture yielded a precipitate which was filtered and stored, while the mixture was washed with water, then with 5% NaOH. The new precipitate was twice extracted with CH2Cl2, the extract anhydrified, concentrated, joined to the previously filtered solid and both were dissolved in CH2Cl2 and treated with diethylamine (120 ml, 1.15 moles). After 24 hours it was extracted with 10% HCl and the phases were separated and extracted with CH2Cl2. The organic phase was washed with 10% NaOH, discoloured with charcoal, anhydrified and concentrated. The residue was dissolved in CH2Cl2 and treated, under stirring, with 10% HCl for 30 minutes. The organic phase was washed with water, anhydrified and dried. The residue was dissolved in CH2Cl2 and treated with 10% NaOH under stirring for 30 minutes. The organic phase was washed with water, anhydrified and concentrated to give a solid which was crystallised from CH3OH/H2O 65:35 and dried at 50° C. over P2O5, then crystallised again from CH3OH/H2O 6:4 to give 35.28 g of the title compound (yield: 32%). m.p.: 115-117° C.

1. temperatureThe cooling of the mixture
2. customyielded a precipitate which
3. filtrationwas filtered
4. washwas washed with water
5. extractionThe new precipitate was twice extracted with CH2Cl2
6. concentrationthe extract anhydrified, concentrated
7. dissolutionboth were dissolved in CH2Cl2
8. extractionAfter 24 hours it was extracted with 10% HCl
9. customthe phases were separated
10. extractionextracted with CH2Cl2
11. washThe organic phase was washed with 10% NaOH
12. concentrationconcentrated
13. dissolutionThe residue was dissolved in CH2Cl2
14. additiontreated
15. washThe organic phase was washed with water
16. customdried
17. dissolutionThe residue was dissolved in CH2Cl2
18. additiontreated with 10% NaOH
19. stirringunder stirring for 30 minutes
20. washThe organic phase was washed with water, anhydrified
21. concentrationconcentrated
22. customto give a solid which
23. customwas crystallised from CH3OH/H2O 65:35
24. dry with materialdried at 50° C. over P2O5
25. customcrystallised again from CH3OH/H2O 6:4