Calcium Chloride → Secobarbital

Sodium seconal (2 g) was dissolved in a small volume of water and mixed with a conc. aqueous solution of CaCl2. The white precipitate which separated out was filtered, washed with water, then with ether and air dried on the filter funnel. A white powder (2.3 g) assumed to be the Ca salt of seconal was collected. This was dissolved in methanol (50 ml) and, after addition of 1.1 g of sodium chloroacetate and 2 ml DMF, was refluxed for 6 hours, and then allowed to stir at room temperature overnight. After evaporation of the solvent, the residue was treated with water (30 ml) and acidified with conc. HCl. The mixture was extracted with chloroform (3 × 30 ml) and the organic layer evaporated to dryness. The residue was stirred with 30 ml of 10% NaHCO3 solution and then extracted with chloroform. The chloroform extract, on evaporation, yielded 0.82 g of unreacted seconal. The bicarbonate layer was acidified and extracted with chloroform. The organic layer upon evaporation yielded 0.86 g of a gummy material which had an NMR spectrum consistent with the expected acid. This acid was redissolved in 10% NaHCO3 and the above procedure of acidification and chloroform extraction was repeated, leading to a yield of 0.62 g of a colorless gum which slowly crystallized on standing. This material was analytically pure.

1. customThe white precipitate which separated out
2. filtrationwas filtered
3. washwashed with water
4. dry with materialwith ether and air dried on the filter funnel
5. customwas collected
6. dissolutionThis was dissolved in methanol (50 ml)
7. additionafter addition of 1.1 g of sodium chloroacetate and 2 ml DMF
8. temperaturewas refluxed for 6 hours
9. customAfter evaporation of the solvent
10. additionthe residue was treated with water (30 ml)
11. extractionThe mixture was extracted with chloroform (3 × 30 ml)
12. customthe organic layer evaporated to dryness
13. stirringThe residue was stirred with 30 ml of 10% NaHCO3 solution
14. extractionextracted with chloroform
15. extractionThe chloroform extract, on evaporation

ORD record

ord-1622fabe09c34cecb7af333612b219bc

Source dataset

uspto-grants-1976_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03966744