4-Hydroxybenzoic Acid → 4-Hydroxybenzoic acid--water (1/1)

HRID 968990Notes

Reaction equation

[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1>CO>[OH2:1].[OH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 80 °C

Procedure

Three hundred grams of parahydroxybenzoic acid and one thousand and five hundred grams of 10% aqueous methanol solution were put into a 2 L flask, and heated to 80° C. to give a 10% aqueous methanol solution containing parahydroxybenzoic acid. The solution was cooled to 25° C. at a rate of 0.5° C./min, and filtered by using a centrifuge at 25° C. As a result, 324.9 g of crystalline parahydroxybenzoic acid monohydrate was obtained. The water content measured by Karl Fischer's method was 16.6%. The resulting crystalline product was dried with airflow at 70° C., and 268.4 g of crystalline parahydroxybenzoic acid anhydride was obtained.

Workup

temperatureThe solution was cooled to 25° C. at a rate of 0.5° C./min
filtrationfiltered
customat 25° C

Sources & evidence

ORD record: ord-c10972332b564a099371e0bc7e6d3100
Source dataset: uspto-grants-2007_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07304182B2

Reaction notes

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