tert-Butyl acetate → 3-[5-(2,2-Dimethyl-propionylamino)-pyrazin-2-yl]-3-oxo-propionic acid-tert-butyl ester

温度

-20 °C

A 3-necked 1-L round bottomed flask equipped with a magnetic stirrer, addition funnel, thermocouple probe and nitrogen inlet/outlet was charged with 25.00 mL (185.5 mmol) of tert-butyl acetate, 20.00 g (84.30 mmol) of the compound prepared in step 2 and 20 mL of THF. After cooling to −20° C., a solution of 261.4 mL (261.4 mmol) of 10M lithium bis(trimethylsilyl)amide (LHMDS) in THF was added dropwise, while maintaining the temperature of the reaction mixture between −20° C. and 0° C. The resulting red solution was stirred at −20° C. for 40 min. HPLC analysis indicated complete reaction. The mixture was allowed to warm to 0° C., then quenched by the addition of pre-cooled 200 mL (260.3 mmol) of 25 wt % citric acid solution. The organic layer was separated, washed with 2×200 mL of saturated sodium chloride solution and concentrated at 30° C./60 mmHg to a volume of ca. 50 mL. The concentrated solution was diluted with 200 mL of butanone and again concentrated at 30° C./60 mmHg to ca. 50 mL. The concentrate was again diluted with 200 mL of butanone and concentrated at 30° C./60 mmHg to a volume of ca. 100 mL. NMR analysis indicated the absence of THF. The resulting butanone solution of the title compound was used directly in the next step.

1. customA 3-necked 1-L round bottomed flask equipped with a magnetic stirrer, addition funnel
2. temperaturewhile maintaining the temperature of the reaction mixture between −20° C. and 0° C
3. customreaction
4. temperatureto warm to 0° C.
5. customquenched by the addition of pre-cooled 200 mL (260.3 mmol) of 25 wt % citric acid solution
6. customThe organic layer was separated
7. washwashed with 2×200 mL of saturated sodium chloride solution
8. concentrationconcentrated at 30° C./60 mmHg to a volume of ca. 50 mL
9. additionThe concentrated solution was diluted with 200 mL of butanone
10. concentrationagain concentrated at 30° C./60 mmHg to ca. 50 mL
11. additionThe concentrate was again diluted with 200 mL of butanone
12. concentrationconcentrated at 30° C./60 mmHg to a volume of ca. 100 mL

ORDレコード

ord-c52e6a4d4f9a43eb8ee7ebb98fc9064c

出典データセット

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07727750B2