L-Pyroglutamic Acid → HCID 178428106, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (±)-7-(2-chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline (109.3 g) in isopropylalcohol (700 ml) was added dropwise a solution of L-pyroglutamic acid (10 g) in isopropylalcohol (700 ml) at 50° C. for 1.5 hours, and the mixture was stirred at 50° C. for 1 hour and then at room temperature for 2 days. The crystals were filtered and washed with isopropylalcohol to give (−)-7-(2-chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline L-pyroglutamate (55.5 g, 88%ee), which was recrystallized from ethanol to give crystals of L-pyroglutamate (44.3 g, 97%ee). The thus obtained crystals of salt was suspended in methanol (500 ml), and to the suspension was added a solution of 28% sodium methoxide in methanol (10.9 ml). The mixture was stirred at 50° C. for 30 minutes, and under reduced pressure, the solvent was evaporated to give crystals, which were washed with water and dried to give (−)-7-(2-chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline (38.9 g). (This compound was confirmed to be S-isomer (absolute configuration), according to X-ray crystal structure analysis.)

Provenance & Evidence