Ethyl Acetate → HCID 89995490, compound

Temperature

0 °C

To a solution of ethyl 4-bromo-1-((tert-butoxycarbonyl)amino)-1H-imidazole-2-carboxylate (1.90 g, 5.69 mmol) in THF (4.4 ml) at 0° C., was added dropwise a cold (pre-cooled at 0° C.) 1M THF solution of potassium tert-butoxide (17.06 ml, 17.06 mmol). The reaction was stirred at 0° C. for 5 minutes. Dry ethyl acetate (1.410 ml, 14.40 mmol), which was pre-cooled at 0° C., was added dropwise. Stirring was continued at 0° C. for 15 minutes. The ice bath was removed. The reaction was stirred at room temperature for 2 hrs, becoming a darker yellow suspension. The reaction was cooled to 0° C., and treated with 1.0 N HCl via dropwise addition until complete dissolution of the suspension. The reaction was concentrated to half volume under reduced pressure, and diluted with ethyl acetate. The solution was adjusted to basic by addition of 1.0 N NaOH. The aq. layer was back extracted with ethyl acetate (3×). The ethyl acetate extracts were combined, dried with sodium sulfate, filtered, and concentrated to give ethyl 3-(4-bromo-1-((tert-butoxycarbonyl)amino)-1H-imidazol-2-yl)-3-oxopropanoate (1.502 g, 4.00 mmol, 70% yield) as a pale yellow solid. LCMS (Method B) m/z 376.1 [M+1], Br-pattern; HPLC (Method B): Rt 2.961 min. 1H NMR (400 MHz, MeOD, enoate form) δ 7.51 (s, 1H), 4.18 (q, J=7.3 Hz, 2H), 4.00 (s, 1H), 3.97 (s, 1H), 1.49 (br. s., 9H), 1.25 (t, J=7.2 Hz, 3H).

1. additionwas added dropwise
2. stirringStirring
3. waitwas continued at 0° C. for 15 minutes
4. customThe ice bath was removed
5. stirringThe reaction was stirred at room temperature for 2 hrs
6. temperatureThe reaction was cooled to 0° C.
7. additiontreated with 1.0 N HCl via dropwise addition until complete dissolution of the suspension
8. concentrationThe reaction was concentrated to half volume under reduced pressure
9. additiondiluted with ethyl acetate
10. additionbasic by addition of 1.0 N NaOH
11. extractionThe aq. layer was back extracted with ethyl acetate (3×)
12. dry with materialdried with sodium sulfate
13. filtrationfiltered
14. concentrationconcentrated

ORD record

ord-c9f44eb339a3438abeae1ac6b965c986

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09428511B2