Phosgene → 5-[1-(2,4-Dichlorophenoxy)ethyl]-1,3,4-thiadiazol-2-yl isocyanate

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Reaction Steps

A 500 milliliter, neck flask equipped with a magnetic stirrer, thermometer, dry ice condenser/drying tube and inlet from a phosgene (COCl2) tank via a calibrated rotameter was charged with 50 milliliters of ethyl acetate saturated with phosgene at 20° C. (approximately 0.5 mole of phosgene). An additional 100 milliliters of ethylacetate was added and 10.0 grams of 5-[1-(2,4-dichlorophenoxy)ethyl]-2-amino-1,3,4-thiadiazole, (prepared above) was added. The resulting emulsion was stirred for 17 hours; and the flask was purged with nitrogen until no COCl2 was detected and a suspension formed. The solid was removed by filtration and dried in a vacuum oven at 80° C. to 5.9 grams of white crystals of 5-[1-(2,4-dichlorophenoxy)ethyl]-1,3,4-thiadiazol-2-yl isocyanate dimer. (Melting point 176°-179° C.).

Provenance & Evidence