Methyl chloroformate → 5-Butyl-2-(4-isothiocyanatophenyl)pyrimidine

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Reaction Steps

6.77 g of triethylammonium p-(5-butyl-2-pyrimidinyl)phenyldithiocarbamate were largely dissolved in 60 ml of chloroform and 2.5 ml of triethylamine. The mixture was subsequently treated dropwise with 2.00 ml of methyl chloroformate within 5 minutes while stirring and cooling with an ice bath. The ice bath was removed after 10 minutes. After a further 60 minutes the yellowish solution was washed once with 20 ml of 0.5N hydrochloric acid and three times with 20 ml of water each time, dried over sodium sulphate and concentrated. Chromatography of the residue on 60 g of silica gel with hexane/ethyl acetate (vol. 95:5) gave 3.65 g of p-(5-butyl-2-pyrimidinyl)phenyl isothiocyanate which was recrystallized twice from hexane for further purification. Yield 3.17 g; m.p. (C--S) 60.8° C., cl.p. (S--I) 77.8° C.

Provenance & Evidence