Triethylamine → 2-Benzoxazolamine, N-2-propyn-1-yl-

A solution of 2-chlorobenzoxazole (1.53 g, 10 mmol) in CH3CN (5 mL) was added dropwise to a mixture of propargyl amine (550 mg, 9.9 mmol) and Et3N (2.09 mmol, 15 mmol) and CH3CN (10 mL) under N2, and the resulting mixture was heated to reflux for 4 h, then stirred overnight at rt. The mixture was filtered, and the filtrate was partitioned between EtOAc (100 mL) and brine. The aqueous layer was extracted with EtOAc and the combined organic layers were dried (MgSO4) and concentrated to dryness. The crude solid was diluted with heptane (20 mL) and Et2O (50 mL) and the mixture was heated to boiling and filtered hot. The filtrate was concentrated to dryness, then taken up in boiling Et2O (50 mL) and the solution was cooled and filtered. The filtrate was diluted with hexane (125 mL) and cooled to −20° C. for 4 h, and the crystallized product was collected by filtration (1.1 g, 64%). MS (APCI(+)) m/e 173.0 (M+H)+.

1. temperaturethe resulting mixture was heated
2. temperatureto reflux for 4 h
3. filtrationThe mixture was filtered
4. customthe filtrate was partitioned between EtOAc (100 mL) and brine
5. extractionThe aqueous layer was extracted with EtOAc
6. dry with materialthe combined organic layers were dried (MgSO4)
7. concentrationconcentrated to dryness
8. additionThe crude solid was diluted with heptane (20 mL) and Et2O (50 mL)
9. temperaturethe mixture was heated
10. filtrationfiltered hot
11. concentrationThe filtrate was concentrated to dryness
12. temperaturethe solution was cooled
13. filtrationfiltered
14. additionThe filtrate was diluted with hexane (125 mL)
15. temperaturecooled to −20° C. for 4 h
16. filtrationthe crystallized product was collected by filtration (1.1 g, 64%)

ORD record

ord-0077c3dd5ff742728342d75195313b04

Source dataset

uspto-grants-2008_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07468371B2