Dicyclohexylcarbodiimide → HCID 178463103, compound

Participants

Reaction Steps

A 50-ml eggplant type flask was charged with 0.76 g (2.8 mmol) of 4,5,8-trimethylthiochroman-6-carboxylic acid-1,1-dioxide, 0.35 g (2.1 mmol, 1.1 equivalents) of 1-ethyl-5-hydroxypyrazole and 5 ml of t-amyl alcohol, and a solution of 0.70 g (3.4 mmol, 1.2 equivalents) of N,N'-dicyclohexylcarbodiimide (DCC) in 5 ml of t-amyl alcohol was added at room temperature. The mixture was allowed to react at room temperature for 2 hours, then, 0.58 g (2.8 mmol, 1.5 equivalents) of potassium carbonate was added, and the mixture was allowed to react at 100° C. for 6 hours. The solvent was distilled off, the residue was distributed into 30 ml of water and 30 ml of ethyl acetate, and a DCC urea material as an insoluble material was separated by filtration. An organic layer was extracted with 10 ml of a 5% potassium carbonate aqueous solution twice. The aqueous layers were combined and acidified with concentrated hydrochloric acid and thereafter extracted with ethyl acetate. The extract was washed with a saturated sodium chloride aqueous solution and dried over sodium sulfate, and the solvent was distilled off to give 0.77 g of a crude product. The crude product was recrystallized from ethanol to give 0.52 g (yield 51%) of 4,5,8-trimethyl-6-(1-ethyl-5-hydroxypyrazol-4-yl)carbonylthiochroman-1,1-dioxide (Compound No. 44).

Provenance & Evidence