Reaktion #309155

Reaktionsgleichung

2-(4-bromophenyl)-5,8-dioxaspiro[3.4]octane-2-carboxylic acid

2-(4-Bromophenyl)-5,8-dioxaspiro[3.4]octane-2-carboxylic acid

DIPEA

tert-butanol

DPPA

sodium bicarbonate

→

tert-butyl [2-(4-bromophenyl)-5,8-dioxaspiro[3.4]oct-2-yl]carbamate

tert-Butyl [2-(4-bromophenyl)-5,8-dioxaspiro[3.4]oct-2-yl]carbamate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with EtOAc
2. 2
   Trocknendried over sodium sulfate
3. 3
   Filtrationfiltered
4. 4
   Einengenconcentrated
5. 5
   SonstigeThe crude residue was purified by column chromatography
6. 6
   Wascheneluting with 7-50% EtOAc/Hexane
7. 7
   Sonstigethe solvent removed in vacuo

Vorschrift

To a solution of 2-(4-bromophenyl)-5,8-dioxaspiro[3.4]octane-2-carboxylic acid (1-4) (40.7 g, 130 mmol) and DIPEA (22.7 mL, 130 mmol) in tert-butanol (231 mL, 3.25 mol) was added DPPA (35.8 g, 130 mmol) and the reaction was heated to 100° C. overnight under N2. The reaction mixture was poured into saturated sodium bicarbonate, extracted with EtOAc, dried over sodium sulfate, filtered and concentrated. The crude residue was purified by column chromatography eluting with 7-50% EtOAc/Hexane. The appropriate fractions were combined and the solvent removed in vacuo to give tert-butyl [2-(4-bromophenyl)-5,8-dioxaspiro[3.4]oct-2-yl]carbamate (1-5). MS (M+H)+: 385.

Quelle