Reaktion #1878210

Reaktionsgleichung

benzyl bromide

hydrochloric acid

1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone

lithium bis(trimethylsilyl)amide

methyl 3-methylene-5-(phenylsulfonyl)-2,3,4,5-tetrahydro-1-benzoxepin-7-carboxylate

→

methyl 5-benzyl-3-methylene-5-(phenylsulfonyl)-2,3,4,5-tetrahydro-1-benzoxepin-7-carboxylate

Ausbeute 86.0%

Lösungsmittel

tetrahydrofuran

dichloromethane

water

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeprepared
2. 2
   workup.STIRRINGAfter stirring for 5 minutes
3. 3
   SonstigeAfter separating the organic and aqueous phases
4. 4
   Extraktionthe aqueous phase is extracted three times with dichloromethane
5. 5
   WaschenThe combined organic phases are washed with brine
6. 6
   Sonstigeare dried
7. 7
   Einengenare finally concentrated under vacuum
8. 8
   SonstigeThe crude reaction product
9. 9
   Sonstigeis then purified by chromatography on silica gel (ethyl acetate/heptane 25/75)

Vorschrift

0.072 ml (1.1 equivalents) of 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone and then 0.6 ml (1.1 equivalents) of 1.06M lithium bis(trimethylsilyl)amide in tetrahydrofuran are added at ambient temperature to 195 mg (0.55 mmol) of methyl 3-methylene-5-(phenylsulfonyl)-2,3,4,5-tetrahydro-1-benzoxepin-7-carboxylate, prepared according to example 1, in solution in 5 ml of tetrahydrofuran. The reaction medium then assumes a dark yellow color. After stirring for 15 minutes, 0.073 ml (1.1 equivalents) of benzyl bromide is added. After stirring for 5 minutes, water, 1N hydrochloric acid and dichloromethane are added. After separating the organic and aqueous phases, the aqueous phase is extracted three times with dichloromethane. The combined organic phases are washed with brine, are dried and are finally concentrated under vacuum. The crude reaction product is then purified by chromatography on silica gel (ethyl acetate/heptane 25/75) to provide 211 mg (86%) of methyl 5-benzyl-3-methylene-5-(phenylsulfonyl)-2,3,4,5-tetrahydro-1-benzoxepin-7-carboxylate in the form of a white solid; M.p.=164–165° C.

Quelle