Hydrochloric Acid → 1,3-Benzenediol, propyl-

Participants

Reaction Conditions

Reaction Steps

A 12 L round bottom flask equipped with a mechanical stirrer, reflux condenser and nitrogen inlet was charged with of sodium hydroxide (440 g, 11 moles) and 4.5 L of distilled water. Sodium borohydride (440 g, 11.6 moles) was added and the batch was held at 50° C. until all the solids dissolved. To the mixture there was added 2,4-dihydroxypropiophenone (440 g, 2.6 moles) resulting in a 10-15° C. exotherm and some hydrogen evolution. The batch was held at 80° C. for 90 minutes then cooled to 10-20° C. in an ice bath. Hydrogen evolution was observed during the 90 minute hold at 80° C. 1.9 kg of hydrochloric acid (37%) was added drop-wise (hydrogen evolution) bringing the batch to pH 6. The product was extracted into methylene chloride (5×500 mL). The methylene chloride was stripped off and replaced with toluene (2 L). The product was crystallized from toluene to give propyl resorcinol (261.5 g, 1.7 mol, 65% yield).

Provenance & Evidence