A suspension of 8.11 g (16.0 mmol) 1,6-bis[4-(1,3-dithian-2-yl)phenoxy]hexane in 50 ml anhydrous tetrahydrofuran (THF) was prepared under argon in a dry 250-ml three-necked flask with 50 ml dropping funnel, internal thermometer, magnetic stirrer and septum. The suspension was cooled to −10° C. and 14.1 ml of a 2.5 molar solution of n-butyl lithium (35.2 mmol) in hexane added dropwise over a period of 10 min such that the internal temperature did not exceed 0° C. The brown solution was then stirred for 3 h at −10° C. and a solution of 4.90 g (32.0 mmol) trimethylgermanium chloride in 20 ml anhydrous THF added dropwise to it at −5° C. within 5 min. The reaction mixture was stirred for a further 24 h at room temperature. 50 ml water and 150 ml ethyl acetate were then added and the resultant phases separated. The organic phase was washed twice with 50 ml each time and the combined aqueous phases were re-extracted with 50 ml ethyl acetate. Finally, the combined organic phases were washed with 80 ml saturated aqueous NaCl solution and dried over anhydrous sodium sulphate. After separating off the desiccant, the reaction mixture was concentrated on the rotary evaporator and the product dried to constant weight under fine vacuum. 10.9 g (92% of the theoretical value) 1,6-bis{4-[2-(trimethylgermyl)-1,3-dithian-2-yl]phenoxy}hexane was obtained as a pale-yellowish solid (m.p.: 147-153° C.).
