Triethylamine → N-[(1S,1aR,7bR)-4,7-difluoro-1,1a,2,7b-tetrahydro-cyclopropa[c]chromen-1-yl]-N'-[5-(4-fluorobenzoyl)-2-pyridinyl]urea

Participants

Reaction Conditions

Reaction Steps

(1S,1aR,7bS)-4,7-difluoro-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-1-carboxylic acid (40 mg, 0.18 mmol, ˜95% ee) was mixed with toluene (1 ml), triethylamine (1.1 eq), (6-amino-3-pyridinyl)(4-fluorophenyl)methanone (1.1 eq), DPPA (1.1 eq) and bubbled with argon. The reaction mixture was then heated at stirring at 110° C. for 3 h under in a closed vial. The reaction mixture was concentrated by rotary evaporation and purified by column chromatography on silica (30 g, ethylacetate/hexane 1:4). The last fraction collected contained desired product together with starting aminopyridine (25%, NMR data). The mixture was dissolved in methylene chloride and washed with 1N HCl, water and brine. Organic layer was dried over magnesium sulphate. Concentration gave pure product as white powder (30 mg, yield 39%).

Provenance & Evidence