Reaction #77478

Reaction equation

(±)-7-(2-chloro-5-fluorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline

L-pyroglutamic acid

→

(+)-7-(2-chloro-5-fluorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline L-pyroglutamate

Yield 42.0%

Solvents

ethanol

Conditions

Workup

1. 1
   Temperatureheated
2. 2
   Otherto form a uniform solution
3. 3
   Temperatureto cool gradually
4. 4
   OtherThe crystal precipitated
5. 5
   Filtrationwas recovered by a filtration
6. 6
   Washwashed with ethanol

Procedure

A solution of (±)-7-(2-chloro-5-fluorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline (7.1 g) in ethanol (85 ml) was combined with L-pyroglutamic acid (2.72 g) and heated to form a uniform solution. The mixture was allowed to stand to cool gradually, and stirred at room temperature for 14 hours. The crystal precipitated was recovered by a filtration and washed with ethanol to obtain (+)-7-(2-chloro-5-fluorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline L-pyroglutamate (4.1 g). This crystal was suspended in methanol (50 ml) and combined with a 28% solution of sodium methoxide in methanol (1.7 g) and then the solvent was distilled off under reduced pressure. The resultant crystal was washed with water and dried to obtain a crystal (3.1 g). This was dissolved in ethanol (20 ml) and combined with methanesulfonic acid (1.8 g). The solvent was distilled off under reduced pressure, and the resultant crystal was recrystallized from ethanol to obtain (+)-7-(2-chloro-5-fluorophenyl)-5-guanidinoimino-4-methyl-5,6,7,8-tetrahydroquinoline methanesulfonate (Compound H)(3.6 g, 99.3% ee).

Source