Chlorosulfonic acid → HCID 178514331, compound

Participants

Reaction Conditions

Reaction Steps

A 250 mL three-necked round-bottom flask equipped with a magnetic stirrer, water bath, nitrogen inlet and bubbler, thermometer and temperature controller was charged with 3-diazo-4-oxo-3,4-dihydrocoumarin (10.1 g, 53.7 mmol) prepared in accordance with Example 1 and chlorosulfonic acid (75.1 g). The reaction mixture was then heated to 50° C. and maintained at 50° C. for 42 hours, during which time HPLC analysis showed 99% conversion. The reaction was allowed to cool and was poured slowly, in portions, with stirring, into 420 g ice cold ethanol (the temperature of the ethanol slurry was kept below 10° C. throughout the addition). The ethanolic slurry was filtered, and dried in an oven overnight under vacuum at 58° C. to yield 12.5 g of pure 6-chlorosulfonyl-3-diazo-4-oxo-3,4-dihydrocoumarin (81% yield). The product was characterized by 13C NMR, DSC and UV-Vis. The results are as follows: the vacuum dried sample melted at 184.7° C. 13C-NMR in THF-d8 solvent, showed 9 singlet lines at the following chemical shifts, in ppm: 172.693, 1158.932, 157.050, 141.502, 134.467, 126.202, 121.104, 121.091, 77.983. The UV absorption spectrum of the product in THF solvent was determined at a dilution factor, DF=109,182.05 yielding, λ1 max=232 nm, ε1 max=29,532.1 liters/mole cm; and λ2max=288 nm, ε2 max=9,472.8 liters/mole cm.

Provenance & Evidence