反应详情

To the acid of Step 2 (12.0 g, 0.11 mol) in H2O (25 ml) at 0° C., add 40% dimethylamine (12.9 ml, 0.115 mol), then another 12.0 g acid. Stir 10 min., add H2O (50 ml), then 38% formaldehyde (25 ml, 0.31 mol). Allow to warm to room temperature over 18 hr., filter the solid, slurry in H2O (200 ml), and heat at 90° for 2.5 hr. Extract with diethyl ether, acidify the aqueous layer, allow the oil to crystallize, and filter the solid. Dissolve in Et2O, filter and concentrate to obtain the product as a waxy solid. Recrystallize from Et2O:hexane to obtain the title compound, m.p. 82°-3° C.

1. filtration, filter the solid
2. temperatureslurry in H2O (200 ml), and heat at 90° for 2.5 hr
3. extractionExtract with diethyl ether
4. customto crystallize
5. filtrationfilter the solid
6. dissolutionDissolve in Et2O
7. filtrationfilter
8. concentrationconcentrate
9. customto obtain the product as a waxy solid
10. customRecrystallize from Et2O