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

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Reaction Conditions

Reaction Steps

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.

Provenance & Evidence