2-Butanone, 3-bromo- → HCID 57437185, compound

Participants

Reaction Steps

A mixture of 5-methyl-2-thioxo-2,3-dihydro-1H-imidazole-4-carboxylic acid ethyl ester (10.7 mmol) and 3-bromo-2-butanone (10.7 mmol) in EtOH (16 mL) is heated at reflux for 3 h. The solvents are removed in vacuo and POCl3 (161 mmol) is added. The mixture is stirred at reflux for 3 h, concentrated in vacuo and diluted with chloroform. Ice water is added and the mixture is neutralized by addition of Na2CO3. The layers are separated and the aq. layer is extracted with chloroform. The combined organic layers are dried over Na2SO4 and concentrated in vacuo to give a mixture of two regioisomers which are separated by FC (heptane/EtOAc 9/1 to EtOAc). 2,3,6-trimethyl-imidazo[2,1-b]thiazole-5-carboxylic acid ethyl ester is obtained as minor isomer. LC-MS: tR=0.84 min; [M+H]+=239.0.

Provenance & Evidence