Originator
Farial,Nordmark-Werke,W. Germany,1980
Manufacturing Process
38.5 g (0.1 mol) of N-4-indanyl thiourea are dissolved in 250 cc of methanol.
42,6 g (0.3 mol) of methyl iodide are added thereto and the mixture is
refluxed for 2,5 hours. The mixture thereafter is cooled and the solvent is
removed in a rotation evaporator in a vacuum. Thus, 57.5 g of N-4-indanyl-S_x0002_methylisothiuronium hydroiodide (86% of theoretical) are obtained. Melting
point 144°C to 146°C.
33.49 (0.1 mol) of N-4-indanyl-S-methylisothiuronium hydroiodide are mixed
with 9.0 g (0.15 mol) of anhydrous ethylenediamine. The mixture is slowly
heated to 80°C and heating is continued until the termination of the formation
of methylmercaptan (about 4 hours). After cooling the residue is dissolved in
2N hydrochloric acid and the solution is extracted with chloroform. The extract
is discarded and the aqueous phase is rendered alkaline by the addition of
10% soda lye. The resulting solution is extracted with chloroform and the
extract is washed with water, dried over anhydrous sodium sulfate and the
solvent is removed. An oily residue is obtained which upon standing soon
crystallizes.
The product is recrystallized from petroleum ether having a boiling range of
100°C to 140°C in the presence of activated carbon. Thus, 11.1 g of 2-(4-
indanylamino)-2-imidazoline (55% of theoretical) are obtained as the free
base. Melting point 109°C to 113°C.