Tert-Butyl nitrite → 2,3-Dichloro-5-(methylthio)pyridine

Participants

Reaction Steps

A solution of 50.6 g (0.3 mol) of 3-amino-5,6-dichloropyridine in 700 ml of methylene chloride was slowly added dropwise at 40° C. to a solution of 56.6 g (0.6 mol) of dimethyl disulfide and 46.7 g (0.45 mol) of tert-butyl nitrite in 320 ml of dry methylene chloride. The mixture was then stirred for 1 hour at 40° C. and subsequently for another approximately 15 hours at approximately 20° C., whereupon 500 ml of ice-water were added to the reaction mixture. The organic phase which was separated off was washed once with 1 N hydrochloric acid and once with water, dried over sodium sulfate and finally concentrated. After the crude product had been stirred with n-hexane, 21 g of a dark solid were obtained (purity 94% according to GC). After the hexane solution was concentrated, a further 21.3 g of product of value remained which had a purity of 77% (according to GC). Total yield: 62%; m.p.: 66-67° C.; 1H-NMR (in d6 dimethyl sulfoxide): δ [ppm]=2.6 (s, CH3); 8.1 and 8.3 (2×d, pyr H).

Provenance & Evidence