Pyridine → 3-(Tert-butoxycarbonyl)-4-(3-bromophenyl)-4-methyl[1,2,3]-oxathiazolidine-2-oxide

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Reaction Steps

To a solution of SOCl2 (5.7 mL, 2.5 eq) in dry CH3CN (37 mL) under argon was cooled to −40° C. was added tert-butyl 2-(3-bromophenyl)-1-hydroxypropan-2-ylcarbamate (DC3; R4=Me) (10.3 g, 31 mmol) in dry CH3CN (27 mL) was added dropwise, followed by the addition of dry pyridine (12.4 mL, 160 mmol, 5 eq). The mixture was then allowed to warm to RT in 1 h. The mixture was concentrated to about 30 mL. EtOAc (30 mL) was added and the precipitate was filtered off. The filtrate was concentrated in vacuo to give 10.4 g (89%) of 3-(tert-butoxycarbonyl)-4-(3-bromophenyl)-4-methyl-[1,2,3]-oxathiazolidine-2-oxide as a colorless oil. 1H NMR (CDCl3) δ 7.64 (t, J=2.0 Hz, 1H), 7.36-7.53 (m, 2H), 7.24 (m, 1H), 4.52 (q, J=9.5 Hz, 2H), 1.86 (s, 3H), 1.42 (br s, 9H).

Provenance & Evidence