Pyridine → HCID 67246058, compound

Participants

Reaction Steps

To a suspension of 0.47 sodium cyanate in 20 ml acetonitrile was added 0.42 g pyridine and 0.95 g m-methylphenylsulfonylchloride and the mixture was agitated in an ultrasound bath under argon for ca 1 h. The resulting suspension was added to a solution of 0.500 g N-mono-tert.butyloxycarbonylhexamethylenediamine in 10 ml acetonitrile and the mixture was stirred at room temperature for 2 h. The solvent was evaporated and the residue was partitioned between dichlormethane and 1N sodium hydroxide. The phases were separated and the aqueous phase was acidified by addition of citric acid and extracted with dichloromethane. The second organic phase was washed with half concentrated brine and purified by chromatography on silica gel with heptane:ethyl acetate=1:1. The product fractions were collected and evaporated. The residue was taken up in 5 ml trifluoro acetic acid and kept at room temperature for 4 h. The solvent was evaporated and the residue was taken up in methanol and purified by chromatography on silica gel with a gradient of dichloromethane:methanol:ammonia=19:1:0.1 to 7:3:0.2. The product fractions were concentrated under aspirator vacuum whereby crystallisation occurred. The product was recrystallized from methanol to yield 0.180 g of the title compound as white crystals melting at 186.7-187.4° C.

Provenance & Evidence