Citric Acid → HCID 178514158, compound

To a stirring solution of 5-amino-3-phenylpyrazole (5 g,31.4 mmol) in dioxane (100 mL) was added MgO (1.27 g, 31.4 mmol) and a saturated aqueous solution of sodium bicarbonate (100 mL). The heterogeneous mixture was stirred for 30 min, then thiophosgene (2.65 mL, 34.6 mmol) was added dropwise, and the reaction mixture was further stirred vigorously for 15 min until completion. Ammonium hydroxide (25 mL) was then added dropwise, and the reaction mixture was stirred for another 20 min. A 10% aqueous solution of citric acid was added to lower the pH to 6, and the mixture was extracted with ethyl acetate (3×). The organic layer was dried over sodium sulfate, filtered, and adsorbed on silica gel. Purification on silica gel with 10-80% ethyl acetate in hexane as eluent provided 6.22 g (91%) of (5-Phenyl-2H-pyrazol-3-yl)-thiourea as a yellow foam.

1. stirringthe reaction mixture was further stirred vigorously for 15 min until completion
2. stirringthe reaction mixture was stirred for another 20 min
3. extractionthe mixture was extracted with ethyl acetate (3×)
4. dry with materialThe organic layer was dried over sodium sulfate
5. filtrationfiltered
6. customPurification on silica gel with 10-80% ethyl acetate in hexane as eluent

ORD record

ord-6714eb7bd2b64eea8a0149bb3ec4ce3a

Source dataset

uspto-grants-2009_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07473783B2