Formaldehyde → HCID 19817616, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-propargyl-4-oxothiazolidine (5.02 g), paraformaldehyde (1.28 g) and 4-(4-fluorobenzoyl)-piperidine hydrochloride (10.36 g) in triethylamine (7.20 g) and approximately 20 ml sieve-dried dioxane was added 1.06 of cuprous opper chloride. The reaction flask was equipped with a reflux condenser and heated to 80° C. After 3 hours no starting material remained as observed by TLC (1:1, hexane:ethyl acetate). The reaction mixture was cooled to room temperature, diluted with dichloromethane, filtered, and concentrated in vacuo. The residue was taken up in dichloromethane and extracted with acidic aqueous medium. The combined aqueous fractions were basified by addition of Na2CO3 and extracted with dichloromethane. Combined dichloromethane fractions were dried (MgSO4), filtered, and concentrated in vacuo. The residue was dissolved in ethyl acetate and filtered. The oxalate salt was precipitated from ethyl acetate and recrystallized from methanol/ethyl acetate and methanol/toluene to yield 2.34 g of 3-(4-4-(4-fluorobenzoyl)piperidino)-2-butynyl)-4-oxothiazolidine oxalate, m.p. 128.5°-129.5° C.

Provenance & Evidence