Hydrochloric Acid → HCID 10198071, compound

Participants

Reaction Steps

A mixture of 33.6 g (0.3 mol) thiophene-2-carboxaldehyde, 39.9 g (0.3 mol) aminoacetaldehyde diethyl acetal, 0.3 g of 4-toluenesulfonic acid (TsOH) and 200 ml ethanol is placed in a 500 ml flask and heated to reflux. After 2 hours, the reaction is concentrated and the residue dissolved in 250 ml ethanol. Solid NaBH4 (12.5 g, 0.33 mol) is added in small portions. The reaction is refluxed for 11/2 hours, cooled to room temperature and poured into cold water. The product is extracted into CH2Cl2 (2×250 ml). After drying (Na2SO4) and concentration, 66.7 g crude product is obtained as a pale yellow oil. 22.9 g (0.1 mol) of the crude amine is placed in a 500 ml flask along with 11.7 g (0.12 mol) KSCN, 150 ml ethanol, 40 ml water and 15 ml concentrated hydrochloric acid. After refluxing for 5 hours, the reaction is poured onto 1 liter of ice water. The white crystals are collected and dried to give 12.0 g (61%) product, mp 128°-130° C. (EtOH).

Provenance & Evidence