反应详情

A racemic mixture of 2.9 g of (4RS)-4-(2-pyrazinylmethyl)-4,5-dihydro-2-thiazolyl-amine dihydrochloride is separated on a Chiralcel OD10μ column in a heptane/ethanol/triethylamine mixture (80/20/0.1 by volume). The fractions containing the expected product are concentrated under reduced pressure (1 kPa) at a temperature in the region of 40° C. The residue obtained is dissolved in 5 cm3 of ethanol, followed by addition of 6 cm3 of hydrochloric acid dissolved in diethyl ether and 15 cm3 of diethyl ether. After filtration, washing with 15 cm3 of diethyl ether and drying, 0.371 g of (+)-(4R)-4-(2-pyrazinyl-methyl)-4,5-dihydro-2-thiazolylamine dihydrochloride is obtained in the form of a beige-colored solid melting at 154° C. [1H NMR spectrum (300 MHz, (CD3)2SO-d6, δ in ppm): 3.22 (d, J=6.5 Hz: 2H); 3.45 (dd, J=11.5 and 5.5 Hz: 1H); 3.75 (dd, J=11.5 and 8 Hz: 1H); 4.73 (mt: 1H); 8.60 (broad d, J=2.5 Hz: 1H); 8.63 (dd, J=2.5 and 1.5 Hz: 1H); 8.66 (broad s; 1H); 9.09 (unresolved complex: 1H); 9.58 (unresolved complex: 1H); 9.95 (broad s: 1H); (αD20=+46.3+/−1.1 at a concentration of 0.5% in methanol)].

1. customis separated on a Chiralcel OD10μ column in a heptane/ethanol/triethylamine mixture (80/20/0.1 by volume)
2. additionThe fractions containing the expected product
3. concentrationare concentrated under reduced pressure (1 kPa) at a temperature in the region of 40° C
4. customThe residue obtained
5. filtrationAfter filtration
6. washwashing with 15 cm3 of diethyl ether
7. customdrying