Benzyl chloroformate → ((S)-5-bromo-indan-2-yl)-carbamic acid benzyl ester
Reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[CH2:7][C@H:6]([NH2:11])[CH2:5]2.Cl[C:13]([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14]>ClCCl>[CH2:16]([O:15][C:13](=[O:14])[NH:11][C@@H:6]1[CH2:5][C:4]2[C:8](=[CH:9][CH:10]=[C:2]([Br:1])[CH:3]=2)[CH2:7]1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
(S)-5-Bromo-indan-2-ylamine (1.0 g) suspended in dichloromethane (10 ml) is cooled to 0° C. and benzyl chloroformate (0.74 ml) is added dropwise and the reaction mixture is stirred for 0.5 hour. The solution is filtered to give (S)-(5-Bromo-indan-2-yl)-carbamic acid benzyl ester. PdCl2(dppf)2 (59 mg) is placed in a dry flask under argon and isobutyl zinc bromide (50 ml, 0.5 M solution in THF) is added. (5-Bromo-indan-2-yl)-carbamic acid benzyl ester (2.50 g) is dissolved in dry THF (2 ml) and the solution is added to the reaction mixture. The reaction mixture is stirred at 50° C. for 18 hours then quenched with HCl(aq) (2M) and partitioned between ethyl acetate and water. The organic layer is dried over MgSO4, filtered and the solvent removed in vacuo. The title compound is obtained by flash column chromatography (silica, eluent ethyl acetate/iso-hexane 1:4). 1H nmr (CDCl3, 400 MHz); 7.35 (m, 5H), 7.10 (d, 1H), 7.00 (s, 1H), 6.90 (d, 1H), 5.1 (s, 2H), 4.55 (m, 1H), 3.30 (m, 2H), 2.75 (dt, 2H), 2.45 (d, 2H), 1.80 (m, 1H), 0.90 (d, 6H).