Hydrochloric Acid → 5-[5-(4-Chloro-phenyl)-2-oxo-6H-[1,3,4]oxadiazin-3-ylmethyl]-3-methyl-sulphanyl-1,3-dihydro-indol-2-one

Participants

Reaction Conditions

Reaction Steps

Ethyl(methylsulphanyl)acetate (27.31 mmoles) is added dropwise to a solution of the compound obtained in Step E (23.75 mmoles) in THF (200 ml) at −60° C. under a nitrogen atmosphere. tBuOCl (27.31 mmoles) is added dropwise to the reaction mixture over 20 minutes, keeping the temperature between −60° C. and −55° C. After stirring for 3 hours at −60° C., triethylamine (29.68 mmoles) is added dropwise. The reaction mixture is brought to ambient temperature; aqueous 3M HCl solution (340 ml) is then added and stirring is carried out for a further 2 hours. The organic phase is evaporated and the aqueous suspension is extracted with DCM. The organic phases are combined, then washed with 2M HCl solution and then with saturated NaCl solution, dried over sodium sulphate, filtered and evaporated to dryness. The residue is triturated in ethyl ether, filtered and dried in vacuo to yield the title product, which is used directly in the next Step.

Provenance & Evidence