Hydrochloric Acid → (R)-ethyl-3-(4-chlorophenyl)-hexahydro-1-pyrazinecarboxylate

Temperature

100 °C

To (R)-ethyl-3-(4-chlorophenyl)-4-(2-propenyl)hexahydro-1-pyrazinecarboxylate (212 mg, 0.69 mmol) produced in Example 24, distilled water (2 mL), conc. hydrochloric acid (71 mg, 1.0 equivalent) and ruthenium chloride (7 mg, 0.04 equivalent) were added. The mixture was stirred at 100° C. for 93 hours. After toluene (2 mL) was added thereto, the formed insolubles were separated by filtration and washed with toluene (2 mL) and distilled water (2 mL). To the filtrate, 30 wt % aqueous solution sodium hydroxide (110 mg, 1.2 equivalents) was added. The organic layer and aqueous layer were separated, and the organic layer was washed twice with distilled water (4 mL). The obtained organic layer was concentrated and dried under vacuum, to obtain 72 mg of the title compound as pale brown oil (yield: 38%, chemical purity: 92.6 area %). The retention time in the chemical purity analysis method was 2.9 min.

1. additionwere added
2. customthe formed insolubles were separated by filtration
3. washwashed with toluene (2 mL)
4. distillationdistilled water (2 mL)
5. customThe organic layer and aqueous layer were separated
6. washthe organic layer was washed twice with distilled water (4 mL)
7. concentrationThe obtained organic layer was concentrated
8. customdried under vacuum

ORD record

ord-8e7a6a6f0f2f4d91af0aa6c0b6df5c7c

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08273883B2