Reaktion #2294778

Reaktionsgleichung

KOtBu

acetic acid

7-(benzenesulfonyl)-8-(4-bromo-3-methyl-2-pyridyl)-3-methyl-3,9-diazaspiro[4.4]nonan-4-one

potassium tert-butoxide

→

2-(4-bromo-3-methyl-2-pyridyl)-7-methyl-1,7-diazaspiro[4.4]non-1-en-6-one

Ausbeute 58.1%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe reaction was stirred at 00° C
2. 2
   workup.WAITfor 1 hour
3. 3
   Einengenconcentrated in vacuo
4. 4
   WaschenElution

Vorschrift

To an ice cooled solution of 7-(benzenesulfonyl)-8-(4-bromo-3-methyl-2-pyridyl)-3-methyl-3,9-diazaspiro[4.4]nonan-4-one (which may be prepared as described in Description 8) (3500 mg, 7.54 mmol) in THF (5 mL) was added potassium tert-butoxide (1691 mg, 15.07 mmol) and the reaction was stirred for 1 hour. Additional KOtBu (1.7 g, 15.1 mmol) was added and the reaction was stirred at 00° C. for 1 hour, and allowed to warm to room temperature overnight. The reaction was quenched by addition of acetic acid (3.45 mL, 60.3 mmol), concentrated in vacuo and loaded onto a silica column (100 g SNAP). Elution using EtOAc gave 2-(4-bromo-3-methyl-2-pyridyl)-7-methyl-1,7-diazaspiro[4.4]non-1-en-6-one (1410 mg, 4.3762 mmol, 58.063% yield) as a pale yellow crystalline solid;

Quelle