1,3-Butanedione, 1-(2-thienyl)- → 1,3-Butanedione, 1-(2-thienyl)-

Participants

Reaction Steps

The intermediate 3-amino-1-(2-thienyl)-2-buten-1-one was prepared as follows: A mixture containing 153 g of 1-(2-thienyl)-1,3-butanedione, 176.7 g of ammonium acetate and 1 liter of toluene was azeotroped for five hours and then allowed to cool. The solid that separated from the reaction mixture was collected, washed successively with toluene and ether, and dried in a vacuum oven at 90° C. to yield 122 g of 1-(2-thienyl)-1,3-butanedione, m.p. 167°-171° C. A 10 g sample of this material was dissolved in 300 ml of boiling toluene, the solution treated with decolorizing charcoal and filtered, and the filtrate allowed to cool. The solid that separated was collected and dried in a vacuum oven at 90° C. to yield 5.8 g of 3-amino-1-(2-thienyl)-2-buten-1-one, as off-white needles, m.p. 170°-172° C. The main portion of the product was then dissolved in boiling isopropyl alcohol, the hot solution treated with decolorizing charcoal and filtered, and the filtrate allowed to cool. The solid that crystallized was collected, washed with isopropyl alcohol, dried in a vacuum oven at 80° C. to yield 74.1 g of product melting at 169°-171° C.

Provenance & Evidence