Squaric acid → HCID 178456803, compound

Participants

Reaction Steps

Under agitation, 363.0 g (1.83 moles) of 4-n-propylamino-2,2,6,6-tetramethylpiperidine, 10.8 g (0.095 mole) of quadratic acid, and 150 cc of ethylhexanol were heated in a 1-liter agitated flask with attached water trap for five hours under reflux to boiling; the sump temperature was 205° C., and 3.0 cc of water was removed from the cycle. After concentration of the reaction solution, 33.9 g of crystals was precipitated. Yield: 75.2%, mp 198°-199° C. (from cyclohexane). Extinction (g/l.cm) at 278 nm: 27; at 335 nm: 95.

Provenance & Evidence