Hydrochloric Acid → Bicyclo(2.2.2)octane-1,4-diamine dihydrochloride

A suspension of 1,4-dicarboxybicyclo[2.2.2]octane (9.91 g, 50 mmol) in toluene (225 mL) was azeotroped under a Dean-Stark trap to dryness, then cooled to room temperature under nitrogen and treated with triethylamine (20 mL, 143 mmol) and diphenylphosphoryl azide (33.0 g, 120 mmol). The solution was slowly and cautiously warmed to 80° C. (some exotherm and much evolution of gas observed) and stirred at 80°-90° C. for 3 h, then concentrated in vacuo to remove toluene and the residue cooled on an ice bath and treated with 6N hydrochloric acid (150 mL, 900 mmol). The bath was removed and the mixture stirred at room temperature for 3 h, then partially concentrated to remove most water. Acetonitrile (600 mL) was added, and the suspension was cooled for an hour in a refrigerator, filtered, and the solid rinsed with acetonitrile and dried in vacuo to afford 9.31 g (87%) of subject material as a white solid. [M+H]+=141.3. 1H NMR (d6-DMSO) δ 8.24 (br s, 6H), 1.81 (s, 12H).

1. customwas azeotroped under a Dean-Stark trap to dryness
2. temperaturecautiously warmed to 80° C. (some exotherm and much evolution of gas
3. concentrationconcentrated in vacuo
4. customto remove toluene
5. temperaturethe residue cooled on an ice bath
6. customThe bath was removed
7. stirringthe mixture stirred at room temperature for 3 h
8. concentrationpartially concentrated
9. customto remove most water
10. additionAcetonitrile (600 mL) was added
11. temperaturethe suspension was cooled for an hour in a refrigerator
12. filtrationfiltered
13. washthe solid rinsed with acetonitrile
14. customdried in vacuo

ORD record

ord-c8701b809f684a2e8d0900d92dde9659

Source dataset

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07842707B2