C(N(CC)CC)C.[C:8]([N:12]=[C:13]=[S:14])([CH3:11])([CH3:10])[CH3:9].Cl.Cl.[NH2:17][C@H:18]([CH2:21][C:22]1[CH:23]=[N:24][CH:25]=[CH:26][CH:27]=1)[CH2:19][OH:20]>C(O)C.C(OCC)(=O)C.O.ClCCl>[C:8]([NH:12][C:13]([NH:17][C@H:18]([CH2:21][C:22]1[CH:23]=[N:24][CH:25]=[CH:26][CH:27]=1)[CH2:19][OH:20])=[S:14])([CH3:11])([CH3:10])[CH3:9]22.7 cm3 of triethylamine and then 14 cm3 of tert-butyl isothiocyanate are added dropwise to a suspension, under an inert atmosphere, of 16.51 g of (2R)-2-amino-3-(3-pyridyl)-1-propanol dihydrochloride in 200 cm3 of ethanol. The mixture is then heated at a temperature in the region of 60° C. for 1 hour 30 min. After cooling to a temperature in the region of 20° C., the insoluble material is filtered off on a sinter funnel and the filtrate is then evaporated under reduced pressure (2 kPa) at a temperature in the region of 40° C. A yellow paste is obtained, and is taken up in 200 cm3 of ethyl acetate and 100 cm3 of water. The aqueous phase is extracted and then washed with twice 200 cm3 of ethyl acetate. The organic phases are combined, washed with 3 times 50 cm3 of saturated sodium chloride solution and dried over magnesium sulfate. After filtration and then evaporation under reduced pressure (2 kPa) at a temperature in the region of 40° C., a yellow oil is obtained, which is taken up in dichloromethane and re-evaporated to give 3.25 g of N-(tert-butyl)-N′-[(1R)-2-hydroxy-1-(3-pyridylmethyl)-ethyl]thiourea in the form of a pale yellow foam: [1H NMR spectrum (400 MHz, (CD3)2SO-d6, δ in ppm): 1.41 (s: 9H); 2.84 (mt: 2H); 3.37 (mt: 2H); 4.43 (unres. mult.: 1H); 4.96 (t, J=5 Hz: 1H); 7.24 (d, J=8 Hz: 1H); 7.27 (broad s: 1H); 7.33 (dd, J=8 and 5 Hz: 1H); 7.67 (dt, J=8 and 2 Hz: 1H); 8.42 (dd, J=5 and 2 Hz: 1H); 8.46 (d, J=2 Hz: 1H)].
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