Boron trifluoride etherate → HCID 86753937, compound

Participants

Reaction Steps

To a mixture of 0.60 g of 3,4-dihydro-5,8-dimethyl4-oxo-2H-1-benzothiopyran-6-carboxylic acid 1,1-dioxide in 30 mL of methylene chloride was added 0.24 mL of 1,2-ethanedithiol (purchased from Aldrich Chemical Co.) and 0.35 mL of boron trifluoride diethyl etherate (purchased from Janssen Chimica). The mixture was refluxed overnight and then concentrated under reduced pressure to dryness. To the resulting residue was added 10 mL of dilute hydrochloric acid of pH 1. The mixture was extracted with ethyl acetate, and the combined organic extracts were dried over MgSO4, filtered, and concentrated under reduced pressure to afford 0.62 g of the title compound of Step A as an orange solid which had a melting point >250° C. 1H NMR ((CD3)2SO): δ 2.65 (s, 3H), 2.77 (s, 3H), 2.94 (m, 2H), 3.55-3.80 (m, 6H), 7.50 (s, 1H).

Provenance & Evidence