Sodium Methoxide → HCID 178428104, compound

Participants

Reaction Conditions

Reaction Steps

(±)-7-(2-Chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline hydrochloride (123.9 g) was suspended in methanol (1200 ml) and treated dropwise with a 28% solution of sodium methoxide in methanol (119.2 ml). The mixture was stirred at 50° C. for 30 minutes. The solvent was distilled off under reduced pressure, and the residue was combined with water and then the crystal was recovered by a filtration. The crystal was washed with water and dried to obtain (±)-7-(2-chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline (109.3 g) as a colorless crystal. To a solution of (±)-7-(2-chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline (109.3 g) in isopropyl alcohol (700 ml), a solution of L-pyroglutamic acid (10 g) in isopropyl alcohol (150 m) was added dropwise at 50° C. over a period of 1.5 hours. The mixture was stirred at 50° C. for 1 hour and then at room temperature for 2 days. The crystal was recovered by a filtration and washed with isopropyl alcohol to obtain (−)-7-(2-chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline L-pyroglutamate (55.5 g, 88% ee). A recrystallization from ethanol resulted in an L-pyroglutamate (44.3 g, 97% ee). The crystal of the salt thus obtained was suspended in methanol (500 ml) and combined with a 28% methanol solution of sodium methoxide (10.9 ml). The mixture was stirred at 50° C. for 30 minutes and then the solvent was distilled off under reduced pressure. The crystal obtained was washed with water and dried to obtain (−)-7-(2-chlorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline (38.9 g). (This compound was proven to have an absolute configuration of an S form based in an X-ray crystal structure analysis.)

Provenance & Evidence