反应详情

2-Amino-5-methylbenzoic acid methyl ester (122 mg, 0.79 mmol) and triethylamine (0.28 ml, 1.96 mmol) were dissolved in THF (10 ml). A 20% solution of phosgene in toluene (0.74 ml, 1.6 mmol) was added, causing immediate formation of a white precipitate. After 1 h, excess phosgene was purged with a stream of nitrogen, the vented gas being passed through a base scrubber. Thiophenol (81 μl, 0.79 mmol) was added to this crude isocyanate solution, which was then stirred for 1 h. The mixture was filtered to remove triethylamine hydrochloride, the solid being washed with ether. After concentration of the filtrate, the residue was purified by flash chromatography (5% to 10% EtOAc/petrol) to give 5-methyl-2-phenylsulfanylcarbonylaminobenzoic acid, methyl ester: m/z (ES+) 300 (M−H).

1. customexcess phosgene was purged with a stream of nitrogen
2. filtrationThe mixture was filtered
3. customto remove triethylamine hydrochloride
4. washthe solid being washed with ether
5. customAfter concentration of the filtrate, the residue was purified by flash chromatography (5% to 10% EtOAc/petrol)