Hydrochloric Acid → (1R)-1-phenylbut-3-yn-1-amine hydrochloride

Dissolve (RS)-1-amino-1-phenyl-but-3-yne [Zh. Org. Khim. 18(4), 980-983 (1982) A. Mostamandi, L. A. Remizova, A. L. Pavienkova, I. A. Favorskayal] (20.0 g, 138 mmol) and (-)-5,5-dimethyl-2-hydroxy-4-(2-methoxyphenyl)-1,3,2,-dioxaphosphorinane 2-oxide (35.0 g, 129 mmol) in refluxing ethanol (300 mL). Cool the solution to ambient temperature and collect the precipitate by filtration. Rinse the precipitate with a small amount of isopropanol/ethanol (1/1). Two recrystallizations from ethanol gives (R)-1-amino-1-phenyl-but-3-yne 5,5-dimethyl-2-hydroxy-4-(2-methoxyphenyl)-1,3,2-dioxaphosphorinane 2-oxide salt (21 g). Combine (R)-1-amino-1-phenyl-but-3-yne 5,5-dimethyl-2-hydroxy-4-(2-methoxyphenyl)-1,3,2-dioxaphosphorinane 2-oxide salt (21 g, 50.4 mmol) with a mixture of aqueous 1M potassium hydroxide solution (100 mL) and toluene (50 mL) and stir or 0.75 hour. Separate the layers and extract the aqueous layer with toluene (50 mL), combine the organic layers, dry over (Na2SO4), and filter to obtain a solution. Pass hydrogen chloride gas through the solution until it is saturated and then remove the precipitate by filtration and rinse with toluene. Recrystallize from butanone (120 mL) to give 7.0 g the title compound. Specific rotation [α]2D0 =11.0° (c=0.500, MeOH).

1. customSeparate the layers
2. extractionextract the aqueous layer with toluene (50 mL)
3. dry with materialdry over (Na2SO4)
4. filtrationfilter
5. customto obtain a solution
6. customremove the precipitate
7. filtrationby filtration
8. washrinse with toluene
9. customRecrystallize from butanone (120 mL)

ORD record

ord-22d7eaeaac414fdbb72f502a3b32021e

Source dataset

uspto-grants-1998_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05756762