Carbonic acid, bis(phenylmethyl) ester → HCID 70925639, compound

Temperature

-75 °C

In a flame-dried 50 ml three necked flask under argon atmosphere were dissolved 1.27 g (10.0 mmol) of 5,5-dimethylpyrrolidin-2-one in 10 ml of dry THF. After cooling to −75° C., a 2 M solution of lithium diisopropylamide in THF (10.5 ml, 10.5 mmol) was added dropwise maintaining the temperature below −73° C. The solution was stirred for 1 h at −75° C. Then a solution of dibenzyl carbonate (2.72 g, 11.0 mmol) in 5 ml of THF was added dropwise at −75° C., allowed to warm up to r.t. and stirred for 1 h. The reaction was quenched by addition of 5 ml of saturated ammonium chloride solution. After extraction with ethyl acetate/water, drying over sodium sulfate and concentration; the residue was loaded onto a 50 g prepacked flash chromatography column. After elution with a 10% to 70% ethyl acetate in heptane gradient, the fractions containing the desired product were collected to yield 1.07 g (41%) of the title compound as a light yellow oil, MS: m/e=262.2 (M+H+).

1. temperaturemaintaining the temperature below −73° C
2. temperatureto warm up to r.t.
3. stirringstirred for 1 h
4. customThe reaction was quenched by addition of 5 ml of saturated ammonium chloride solution
5. extractionAfter extraction with ethyl acetate/water
6. dry with materialdrying over sodium sulfate and concentration
7. washAfter elution with a 10% to 70% ethyl acetate in heptane gradient
8. additionthe fractions containing the desired product
9. customwere collected

ORD record

ord-6215a088f48940dd936084aac6b09821

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08957213B2