Toluene → 3,6-Diaza-bicyclo(3.2.0)heptane-6-carboxylic acid tert-butyl ester

Temperature

50 °C

Allyl-(2,2-dimethoxy-ethyl)-carbamic acid benzyl ester. To a 500 mL round-bottomed flask equipped with thermocouple probe, nitrogen inlet, reflux condenser, heating mantle, and mechanical stirring was added (2,2-dimethoxy-ethyl)-carbamic acid benzyl ester (50 g, 209 mmol) in toluene (180 mL). To the resulting solution was added powdered KOH (51.6 g, 920 mmol) and triethylbenzylammonium chloride (0.810 g, 3.55 mmol). A solution of allyl bromide (33.0 g, 275 mmol) in toluene (50 mL) was added dropwise over 10 minutes. The mixture was heated to 50° C. and stirred for 2 days. To the reaction mixture was added water (230 mL) over ten minutes. The layers were separated and the aqueous was extracted with toluene (2×200 mL). The combined organics were washed with brine (1×200 mL), dried with magnesium sulfate, filtered, and concentrated to afford the title compound (57.8 g, 98%). 1H-NMR (CDCl3, 500 MHz): 7.31 (m, 5H), 5.76 (m, 1H), 5.15 (m, 4H), 4.51 (m, 1H), 3.98 (d, J=9.48, 2H), 3.36 (m, 8H).

1. customTo a 500 mL round-bottomed flask equipped with thermocouple probe, nitrogen inlet
2. temperaturereflux condenser
3. temperatureheating mantle
4. additionTo the resulting solution was added
5. stirringstirred for 2 days
6. customThe layers were separated
7. extractionthe aqueous was extracted with toluene (2×200 mL)
8. washThe combined organics were washed with brine (1×200 mL)
9. dry with materialdried with magnesium sulfate
10. filtrationfiltered
11. concentrationconcentrated

ORD record

ord-4c93df1c45a04348909210ea2e369b11

Source dataset

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08680275B2