Hydrochloric Acid → 1,3-Benzenediol, propyl-

HRID 1179099Notes

Reaction equation

[OH-:1].[Na+].[BH4-].[Na+].[CH3:5][CH2:6][C:7]([C:9]1[CH:14]=[CH:13][C:12](O)=[CH:11][C:10]=1[OH:16])=O.[H][H].Cl>O>[CH2:7]([C:9]1[C:14]([OH:1])=[CH:13][CH:12]=[CH:11][C:10]=1[OH:16])[CH2:6][CH3:5]

Participants

Conditions

Temperature: 15 °C

Procedure

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).

Workup

customA 12 L round bottom flask equipped with a mechanical stirrer
temperaturereflux condenser and nitrogen inlet
customwas held at 50° C. until all
dissolutiondissolved
customresulting in a 10-15° C. exotherm
customwas observed during the 90 minute
customhold at 80° C
extractionThe product was extracted into methylene chloride (5×500 mL)
customThe product was crystallized from toluene

Sources & evidence

ORD record: ord-54642f08446046799564eb3cbc005a57
Source dataset: uspto-grants-2007_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07279264B2

Reaction notes

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