Sodium Carbonate → HCID 68948397, compound

Participants

Reaction Steps

Mix 3-iodo-4,5-dihydro-thieno[2,3-c]pyran-7-one (1.0, 3.57 mmol) and methyl boronic acid (428 mg, 7.14 mmol) in 7:3:1 dimethoxyethane:water:EtOH (10 mL) and add 2.0 M Na2CO3 (3.5 mL). Bubble dry argon gas through the reaction mixture for 10-15 min to remove oxygen. Add Pd(PPh3)4 (210 mg, 0.18 mmol) and heat using microwave irradiation to 130° C. for 45 min. Pour into 1 N NaOH (50 mL) and wash with hexanes (50 mL). Acidify the aqueous layer with 5N HCl until pH=1 and extract with EtOAc (3×50 mL). Wash the combined organic extracts with brine (50 mL). Concentrate, then add toluene (35 mL) to the crude intermediate. Add p-toluenesulfonic acid monohydrate (339 mg, 1.8 mmol) and heat to 80° C. overnight. Cool to RT, pour into aqueous NaHCO3 (100 mL) and extract with EtOAc (3×100 mL). Wash the combined extracts with brine (100 mL). Dry the organic portion, filter and concentrate. Purify using silica gel chromatography (0-50% EtOAc/hexanes) to provide 133 mg (22%) of the desired product. ES/MS m/z 169.3 [M+H]+.

Provenance & Evidence