Acetone → Potassium Clavulanate

Lithium clavulanate (7.15 g, estimated purity 68% pfa; 0.025 M) was stirred in water (45 mls) and about 200 mg insoluble material filtered off. The filtrate (dark brown) was chilled in an ice bath and the potassium phosphate (10.1 mls of 1 M solution; 1.2 equivalents) added in one lot. Isopropanol (32 mls) was added over 1/2 hr by which time some gummy material separated out. The mixture was made up to 100 ml with acetone over 1/4 hr and transferred to another vessel leaving behind a pale gummy deposit. The decanted liquor was then made up to 800 ml with acetone causing the precipitation of highly coloured (brown) gummy material which was separated off via filtration with celite (4 gm). The clear pale yellow solution was then added to acetone (1750 ml) over 1 hr, stirring vigorously and the mixture was then filtered to afford a pale yellow solid which was washed with acetone (3×50 ml) and dried on a fluid bed dryer to yield potassium clavulanate (2 g, 81.2% pfa, 33% recovery).

1. filtrationabout 200 mg insoluble material filtered off
2. temperatureThe filtrate (dark brown) was chilled in an ice bath
3. customseparated out
4. waitThe mixture was made up to 100 ml with acetone over 1/4 hr
5. customtransferred to another vessel
6. customleaving behind a pale gummy deposit
7. customthe precipitation of highly coloured (brown) gummy material which
8. customwas separated off via filtration with celite (4 gm)
9. additionThe clear pale yellow solution was then added to acetone (1750 ml) over 1 hr
10. filtrationthe mixture was then filtered
11. customto afford a pale yellow solid which
12. washwas washed with acetone (3×50 ml)
13. customdried on a fluid bed dryer

ORD record

ord-a3a789e875744401bdd80f488f9bf49c

Source dataset

uspto-grants-1981_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04255332