Trifluoroacetic acid → (S)-2'-bromo-7'-iodo-2,6-dihydrospiro[[1,4]oxazine-3,9'-xanthen]-5-amine

Participants

Reaction Steps

In a 150-mL resealable vessel, the (S)-tert-butyl 2′-bromo-7′-iodo-2,6-dihydrospiro[[1,4]oxazine-3,9′-xanthene]-5-ylcarbamate (1.475 g, 2.58 mmol) was dissolved in dcm (10 mL), and 2,2,2-trifluoroacetic acid (1.989 mL, 25.8 mmol) was added. The vessel was sealed and placed in a 50° C. oil bath. After 2 h, the reaction was concentrated and the mixture was neutralized with 0.5 M aqueous Na2CO3 (15 mL) and the aqueous phase was extracted with 5% MeOH-dcm (3×33 mL). The organics were combined, washed with dilute brine (10 mL), dried over sodium sulfate and concentrated. The residue was purified by chromatography (5.5% MeOH/DCM) to afford (S)-2′-bromo-7′-iodo-2,6-dihydrospiro[[1,4]oxazine-3,9′-xanthen]-5-amine (151 mg, 0.321 mmol). MS (m/z) 471/473 (M+H)+.

Provenance & Evidence