Acetone → Methyl 3-Azidomethyl-2-thienyl Ketone

Reaction equation

Br[CH2:2][C:3]1[CH:7]=[CH:6][S:5][C:4]=1[C:8]([CH3:10])=[O:9].CC(C)=O.[N-:15]=[N+:16]=[N-:17].[Na+]>O>[N:15]([CH2:2][C:3]1[CH:7]=[CH:6][S:5][C:4]=1[C:8]([CH3:10])=[O:9])=[N+:16]=[N-:17]

Participants

Procedure

To a solution of methyl 3-bromomethyl-2-thienyl ketone (5 g., 0.023 mole) in 42 ml. of acetone and 4 ml. of water was added sodium azide (1.56 g., 0.024 mole) with caution (exothermic!). The resulting solution was stirred at room temperature for 2.5 hours, the acetone evaporated, the residue diluted with water and extracted with diethyl ether. The combined extracts were washed with water, saturated sodium bicarbonate solution and saturated sodium chloride solution, dried over magnesium sulfate and the dried extracts evaporated to dryness to obtain 4.0 g. (97%) of yellow oil. 1H--NMR (CDCl3), ppm. (δ): 7.5 (d, J=5, aromatic-H), 7.2 (d, J=5, aromatic-H), 4.75 (s, CH2N3), 2.5 (s, CH3); IR spectrum (film, cm.-1 : 3100, 2100 (N3), 1660, 1525 and 1420.