Reaktion #2122493

Reaktionsgleichung

ethyl chloroformate

4-Hydroxy-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1-thia-8-aza-spiro[4.5]dec-3-en-2-one

4-hydroxy-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1-thia-8-aza-spiro[4.5]dec-3-en-2-one

triethylamine

→

carbonic acid ethyl ester 8-methoxy-2-oxo-3-(2,4,6-trimethyl-phenyl)-1-thia-8-aza-spiro[4.5]dec-3-en-4-yl ester

Ausbeute 29.7%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigepartitioned between saturated aqueous sodium bicarbonate and t-butylmethyl ether
2. 2
   Trocknenthe organic layer dried over sodium sulfate
3. 3
   Sonstigethe solvent evaporated
4. 4
   SonstigeThe residue was purified by chromatography on silica gel with ethylacetate/cyclohexane (1:2) as a solvent

Vorschrift

94 mg 4-Hydroxy-8-methoxy-3-(2,4,6-trimethyl-phenyl)-1-thia-8-aza-spiro[4.5]dec-3-en-2-one (from Step 7) and 43 mg triethylamine were dissolved in 10 ml tetrahydrofuran, and a solution of 32 mg ethyl chloroformate in 5 ml tetrahydrofuran was added dropwise. The mixture was stirred at ambient temperature for 18 hours, then partitioned between saturated aqueous sodium bicarbonate and t-butylmethyl ether, the organic layer dried over sodium sulfate, and the solvent evaporated. The residue was purified by chromatography on silica gel with ethylacetate/cyclohexane (1:2) as a solvent, to give 34 mg carbonic acid ethyl ester 8-methoxy-2-oxo-3-(2,4,6-trimethyl-phenyl)-1-thia-8-aza-spiro[4.5]dec-3-en-4-yl ester (title compound P1.7) as a solid, mp 87-89° C.

Quelle