Chlorotrimethylsilane → HCID 12769232, compound

Temperature

-50 °C

A solution of 1.54 ml (11 mmoles) of diisopropylamine in 30 ml of dry THF is cooled to -78° C. in dry-ice/acetone bath; 6.11 ml (11 mmoles) of 1.8 M methyllithium is added dropwise under nitrogen. The resulting solution is stirred at the same temperature for 1 hour; 1.55 g (10 mmol) of the bicyclic azetidinone I in 10 ml of dry THF is added dropwise. The mixture is stirred for 1 hr at -78° C. Then 2.17 g (11 mmoles) of tosylazide in 5 ml of dry THF is added dropwise. The resulting mixture is warmed to -50° C. and kept for 1.5 hrs at that temperature; 2.54 ml (20 mmol) of trimethylchlorosilane is added and the mixture is heated at reflux for 6 hrs. The reaction mixture is cooled and the solid is filtered off and washed with 2×25 ml of ether. The filtrate is concentrated. The residue is taken up in 100 ml of water and extracted with 3×25 ml of methylene chloride. The combined extracts are dried over anhydrous MgSO4 and concentrated to give a glue which is chromatographed on silica gel (eluant 50:50 ethylacetate:cyclohexane) to give the desired 7-azido-8-oxo-2,2-dimethyl-3-oxa-1-azabicyclo[4.2.0]octane, II, as a solid (45% yield).

1. stirringThe mixture is stirred for 1 hr at -78° C
2. waitkept for 1.5 hrs at that temperature
3. temperaturethe mixture is heated
4. temperatureat reflux for 6 hrs
5. temperatureThe reaction mixture is cooled
6. filtrationthe solid is filtered off
7. washwashed with 2×25 ml of ether
8. concentrationThe filtrate is concentrated
9. extractionextracted with 3×25 ml of methylene chloride
10. dry with materialThe combined extracts are dried over anhydrous MgSO4
11. concentrationconcentrated
12. customto give a glue which
13. customis chromatographed on silica gel (eluant 50:50 ethylacetate:cyclohexane)

ORD record

ord-be75b64b52dc4605868917ff2e8c9a31

Source dataset

uspto-grants-1981_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04298741