Acetic Acid → HCID 69481564, compound

A mixture of tert-butyl (S)-4-(6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethyl)piperazine-1-carboxylate prepared in Example 394 (100 mg, 0.27 mmol) and trifluoroacetic acid (2 ml) was stirred at room temperature for 3 hours. The reaction mixture was concentrated under reduced pressure. The residue was dissolved in methylene chloride (5 ml) and neutralized with triethylamine (1 ml, 7.17 mmol), and then the solution was concentrated under reduced pressure. The residue was dissolved in methanol (5 ml), and the solution was added 4-trifluoromethylbenzaldehyde (148 mg, 0.85 mmol), sodium cyanotrihydroborate (53 mg, 0.85 mmol), and acetic acid (49 μl, 0.85 mmol) in this order followed by stirring at room temperature for 18 hours. The reaction mixture was concentrated under reduced pressure. To the residue, a saturated sodium hydrogencarbonate solution was added, and the solution was extracted with methylene chloride twice. The organic phases were combined, washed with a saturated sodium hydrogencarbonate solution and a saturated saline solution in this order, dried over magnesium sulfate and then filtered. The filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (methylene chloride/ethyl acetate=1/1) to afford (S)-6-nitro-2-[4-(4-trifluoromethylbenzyl)piperazin-1-ylmethyl]-2,3-dihydroimidazo[2,1-b]oxazole (53 mg, yield 46%) as a light yellow powder.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. dissolutionThe residue was dissolved in methylene chloride (5 ml)
3. concentrationthe solution was concentrated under reduced pressure
4. dissolutionThe residue was dissolved in methanol (5 ml)
5. stirringby stirring at room temperature for 18 hours
6. concentrationThe reaction mixture was concentrated under reduced pressure
7. additionTo the residue, a saturated sodium hydrogencarbonate solution was added
8. extractionthe solution was extracted with methylene chloride twice
9. washwashed with a saturated sodium hydrogencarbonate solution
10. dry with materiala saturated saline solution in this order, dried over magnesium sulfate
11. filtrationfiltered
12. concentrationThe filtrate was concentrated under reduced pressure
13. customthe residue was purified by silica gel column chromatography (methylene chloride/ethyl acetate=1/1)

ORD record

ord-ad8060af35294e9ba9f634497d2a4333

Source dataset

uspto-grants-2007_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07262212B2