Urea → Benzenepropanal

5-Benzyl-oxazol-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 (1.6 g, 9.2 mmol, 9.2% from 3-phenyl-propionaldehyde). ESI-MS m/z calc. 174.1, found 175.1 (M+1)+; 1H NMR (CDCl3) δ 7.32-7.22 (m, 5H), 6.39 (s, 1H), 4.72 (bs, 2H), 3.84 (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 record

ord-699f7df13123456b865f4a7934e289b9

Source dataset

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07977322B2