Acetic Anhydride → ethyl 2-acetyl-3-methylbut-2-enoate
Reaction equation
[C:1]([CH:4]([C:10](=O)[CH3:11])[C:5]([O:7][CH2:8][CH3:9])=[O:6])(=[O:3])[CH3:2].[CH3:13][Mg]Br.C(OC(=O)C)(=O)C>CCOCC>[C:10](=[C:4]([C:1]([CH3:2])=[O:3])[C:5]([O:7][CH2:8][CH3:9])=[O:6])([CH3:11])[CH3:13]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of ethyl diacetyl-acetate maintained at 5°-10° [which can be prepared according to the method described in Helv. Chim. Acta, 35, 2280 (1952)] in 400 ml of anhydrous ether there were added 110 ml (0.33 mole) of a solution of 3 M methyl-magnesium bromide in ether. The reaction mixture was stirred for 24 hours at room temperature. After cooling, 50 ml of acetic acid anhydride were added and the whole was allowed to stand for 2 hours at room temperature, whereupon it was poured into ice-water. After separation, the organic phase was washed with a 5 % aqueous solution of NaOH, then with water, whereupon it was dried (Na2SO4) and concentrated. The subsequent distillation of the residue yielded 16.1 g (63 %) of ethyl α-isopropylidene-acetoacetate, b.p. 94°-98° /8 Torr. A pure sample was obtained by purification of the said product by chromatography on a colum (silica gel and benzene) followed by vapour phase chromatography.
Workup
- customcan be prepared
- temperatureAfter cooling
- waitto stand for 2 hours at room temperature, whereupon it
- customAfter separation
- washthe organic phase was washed with a 5 % aqueous solution of NaOH
- dry with materialwith water, whereupon it was dried (Na2SO4)
- concentrationconcentrated
- distillationThe subsequent distillation of the residue
Sources & evidence
- ORD record
- ord-09399fe9a3ae495fb8ab9cbffc4add4f
- Source dataset
- uspto-grants-1977_06
- Patent number
- US04028278
Reaction notes
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