Bis-(1H-imidazol-2-YL)-methanone → ethyl (4R)-2-oxo-1,3-thiazolidine-4-carboxylate

To a solution of 3-1 (8.5 g, 22.6 mmol) in 200 mL THF was added of carbonyl diimidazole (12.5 g) and the solution was stirred overnight at room temperature. The solution was concentrated in vacuo, 200 mL of 5% Na2CO3 was added and the solution stirred for one hour whereupon 6M HCl was added until the pH of the solution remained at 2. The solution was extracted with EtOAc, the organic phases were then combined, dried over MgSO4, filtered and concentrated in vacuo. The compound was purified by flash chromatography using 40% EtOAc/hexanes to yield 6.7 g of 3-2 as a colorless oil. 1H NMR (400 MHz, acetone-d6): δ 7.5 (br s, 1H), 4.5 (dd, 1H), 4.2 (q, 2H), 3.8 (dd, 1H), 3.6 (dd, 1H), 1.2 (t, 3H).

1. concentrationThe solution was concentrated in vacuo, 200 mL of 5% Na2CO3
2. additionwas added
3. stirringthe solution stirred for one hour whereupon 6M HCl
4. additionwas added until the pH of the solution
5. extractionThe solution was extracted with EtOAc
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe compound was purified by flash chromatography

ORD record

ord-8db284ef410640a9afa0edb4ec88ab74

Source dataset

uspto-grants-2006_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07109223B2