反应详情

N-benzyloxycarbonyl-N-isopropylaminoacetaldehyde diethyl acetal (9 g) and 3,4-dihydroxyphenethylamine hydrochloride (4.5 g) were added to a mixture of n-butyl alcohol (100 ml) and water (15 ml) and then the mixture was refluxed for 6 hours. The above-mentioned acetal (2 g) was added thereto and the resultant mixture was refluxed for 1.5 hours. The solvent was distilled off from the reaction mixture. To the residue was added a mixed solvent of isopropyl alcohol, methanol and ether. The crystals obtained were recrystallized from the same mixed solvent to give 1-(N-benzyloxycarbonyl-N-isopropylaminomethyl)-7,8-dihydroxy-1,2,3,4-tetrahydroisoquinoline hydrochloride (1.6 g), mp 200° to 205° C. (dec). The mother liquor was concentrated and allowed to stand to give 1-(N-benzyloxycarbonyl-N-isopropylaminomethyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline hydrochloride (4.4 g), colorless crystals, mp 207° to 210° C. (dec).

1. temperaturethe mixture was refluxed for 6 hours
2. distillationThe solvent was distilled off from the reaction mixture
3. additionTo the residue was added a mixed solvent of isopropyl alcohol, methanol and ether
4. customThe crystals obtained
5. customwere recrystallized from the same mixed solvent