Sulfuric Acid → 1-(3-n-Butoxy-2-hydroxypropyl)-5-ethyl-5-phenyl-(1H,3H,5H)-pyrimidine-2,4,6-trione

A solution of phenobarbital (69.6 g, 0.3 mole) in dimethylformamide (60 ml) containing triethylamine (20.2 g, 0.2 mole) was stirred with 1-chloro-3-n-butoxy-2-propanol (33.2 g, 0.2 mole) for 6 hours at 70° C. The reaction mixture was then poured into 3% sulphuric acid (500 ml) and the precipitated product was extracted with toluene (200 ml) at 70° C. The toluene layer was separated, washed with 3% aqueous sulphuric acid (200 ml) and left overnight at 4° C. The precipitated phenobarbital was filtered off and filtrate extracted with 5% aqueous sodium carbonate (5×100 ml). The organic layer was then extracted with 1M aqueous sodium hydroxide (2×200 ml), the aqueous layers collected, washed with toluene (100 ml) and the pH was adjusted to 3 with sulphuric acid. The precipitated product was extracted with toluene (150 ml), the organic layer was separated, dried and evaporated under reduced pressure to give the title compound (38.5 g, 53%); purity by HPLC 96.5% .

1. extractionthe precipitated product was extracted with toluene (200 ml) at 70° C
2. customThe toluene layer was separated
3. washwashed with 3% aqueous sulphuric acid (200 ml)
4. filtrationThe precipitated phenobarbital was filtered off
5. extractionfiltrate extracted with 5% aqueous sodium carbonate (5×100 ml)
6. extractionThe organic layer was then extracted with 1M aqueous sodium hydroxide (2×200 ml)
7. customthe aqueous layers collected
8. washwashed with toluene (100 ml)
9. extractionThe precipitated product was extracted with toluene (150 ml)
10. customthe organic layer was separated
11. customdried
12. customevaporated under reduced pressure

ORD-Eintrag

ord-e726e6ac9f05453f95faec9db4973de4

Quelldatensatz

uspto-grants-1993_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05262402