Ethanone, 1-(3,5-dimethyl-4-isoxazolyl)- (9CI) synthesis

11synthesis methods

Product Name:Ethanone, 1-(3,5-dimethyl-4-isoxazolyl)- (9CI)
CAS Number:35166-20-2
Molecular formula:C7H9NO2
Molecular Weight:139.15

3,5-DiMethyl-isoxazole-4-carboxylic acid Methoxy-Methyl-aMide

1223452-45-6
11 suppliers
$90.00/100mg

75-16-1
264 suppliers
$12.00/10ml

Ethanone, 1-(3,5-dimethyl-4-isoxazolyl)- (9CI)

35166-20-2
22 suppliers
$175.00/100mg

Yield:35166-20-2 420 mg

Reaction Conditions:

Stage #1: N-methoxy-N-methyl-3,5-dimethylisoxazole-4-carboxamide;methylmagnesium bromide in tetrahydrofuran at 0 - 20; for 4 h;
Stage #2: with hydrogenchloride in tetrahydrofuran;water at 20; for 1 h;

Steps:

4.2 1-(3,5-dimethylisoxazol-4-yl)ethanone

A solution of 580 mg (3.15 mmol) of N-methoxy-N-methyl-3,5-dimethylisoxazole-4-carboxamide in 20 mL of THF is cooled to 0°C. A solution of 1.57 mL (4.72 mmol) of 3 M methylmagnesium bromide in ether is added. After stirring for 4 hours at room temperature, the reaction medium is taken up in 10 mL of 1 N HCl and stirred for a further 1 hour at room temperature. The mixture is then basified with K₂CO₃ and extracted with ethyl acetate. The organic phase is dried over magnesium sulfate and evaporated to dryness to give 420 mg of 1-(3,5-dimethylisoxazol-4-yl)ethanone, corresponding to the following characteristics: LC/MS (method G): [M+H]+: m/z 140 tr (min) = 1.06. ¹H NMR spectrum (300 MHz, δ in ppm, CDCl₃): 2.48 (s, 6H), 2.70 (s, 3H).

References:

WO2013/190123,2013,A1 Location in patent:Page/Page column 48; 49