Urea → Benzenepropanal

5-Benzyl-thioxazol-2-ylamine A mixture of 2-bromo-3-phenylpropionaldehyde (14.2 g, crude from above) and urea (7.2 g, 0.12 mol) were heated at reflux for 15 hours in 200 mL of ethanol. The solvent was evaporated to dryness and the residue was diluted with dichloromethane (250 mL) and then washed with sodium hydroxide (10% aqueous solution, 100 mL) and water (50 mL). The organic layer was washed three times with hydrochloric acid (5% aqueous solution, 250 mL). The combined aqueous layers were brought to pH 9 to 10 with a 10% aqueous solution of sodium hydroxide and then extracted three times with dichloromethane (300 mL). The organic layer was dried over sodium sulfate, evaporated to dryness, and purified by silica gel column chromatography to give a pale yellow solid (5.2 g, 27 mmol, 27% from 3-phenyl-propionaldehyde). ESI-MS m/z calc. 190.1. found 191.2 (M+1)+; 1H NMR (CDCl3) δ 7.32-7.21 (m, 5H), 6.79 (s, 1H), 4.91 (bs, 2H), 3.95 (s, 2H).

1. temperaturewere heated
2. customThe solvent was evaporated to dryness
3. additionthe residue was diluted with dichloromethane (250 mL)
4. washwashed with sodium hydroxide (10% aqueous solution, 100 mL) and water (50 mL)
5. washThe organic layer was washed three times with hydrochloric acid (5% aqueous solution, 250 mL)
6. extractionextracted three times with dichloromethane (300 mL)
7. dry with materialThe organic layer was dried over sodium sulfate
8. customevaporated to dryness
9. custompurified by silica gel column chromatography

ORD-Eintrag

ord-b5ab85abb6bc4ae0b465d960e5e57fd0

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08541453B2