Methanesulfonic Acid → HCID 58424601, compound

Participants

Reaction Steps

The above mixture of 2-(6-bromo-2-phenylchroman-4-ylidene)ethyl carbamimidothioate HCl salt and thiourea is dissolved in TFA (4 mL) containing MeSO3H (0.4 mL) and stirred at rt for 1 h. The solvent is removed under reduced pressure. The residue is dissolved in ethyl acetate and washed with sat NaHCO3. The separated aqueous phase is extracted with ethyl acetate once and the combined organic phases are washed with brine, and dried over Na2SO4, and filtered. The filtrate is concentrated to give crude 6-bromo-2-phenyl-5′,6′-dihydrospiro[chroman-4,4′-[1,3]thiazin]-2′-amine, which is used for next step without further purification.

Provenance & Evidence