Hydrochloric Acid → (R)-1-[3-(2-Pyrrolidinyl)-2-propynyl] pyrrolidine, dihydrochloride

Temperature

80 °C

A mixture of 7.0 g of (R)-2-[3-(1- pyrrolidinyl)-1-propynyl]-1-pyrrolidinecarboxylic acid, 1,1-dimethylethyl ester, 61 ml of ethanol and 61 ml of 2N hydrochloric acid is heated at 80° C. for one hour. The reaction is concentrated in vacuo and the residue is extracted with methylene chloride. The aqueous layer is concentrated in vacuo, made basic with 10N sodium hydroxide and extracted with methylene chloride. The methylene chloride solution is dried over sodium sulfate, filtered and concentrated in vacuo. The residue is dissolved in methanol, treated with an excess of methanolic hydrogen chloride and precipitated with the addition of diethyl ether. The dihydrochloride is recrystallized from hot methanol to give pure product, mp 198°-200° C. with decomposition, [α]D26° =+21°±1 (C=1.012%, methanol).

1. concentrationThe reaction is concentrated in vacuo
2. extractionthe residue is extracted with methylene chloride
3. concentrationThe aqueous layer is concentrated in vacuo
4. extractionextracted with methylene chloride
5. dry with materialThe methylene chloride solution is dried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. dissolutionThe residue is dissolved in methanol
9. additiontreated with an excess of methanolic hydrogen chloride
10. customprecipitated with the addition of diethyl ether
11. customThe dihydrochloride is recrystallized from hot methanol
12. customto give pure product, mp 198°-200° C. with decomposition, [α]D26° =+21°

ORD record

ord-1212f309045b4a95affb6168ede9a450

Source dataset

uspto-grants-1991_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05001142