Aluminum(III) Chloride → 4,5,7,8-Tetrahydro-thieno[2,3-d]azepine-6-carboxylic acid ethyl ester
Reaction equation
[Al+3].[Cl-].[Cl-].[Cl-].[CH2:5]([O:7][C:8]([N:10]1[CH2:16][C:15](=O)[C:14]2[CH:18]=[CH:19][S:20][C:13]=2[CH2:12][CH2:11]1)=[O:9])[CH3:6]>C(Cl)Cl>[CH2:5]([O:7][C:8]([N:10]1[CH2:16][CH2:15][C:14]2[CH:18]=[CH:19][S:20][C:13]=2[CH2:12][CH2:11]1)=[O:9])[CH3:6]Participants
4
Procedure
AlCl3 (3.95 g, 29.7 mmol) was added to 50 mL DCM at 0° C. Borane-t-butyl amine complex (5.2 g, 59.5 mmol) was added followed by the product of step (c) (2.37 g, 9.9 mmol) dissolved in DCM (50 mL). The reaction was stirred for 2 hours at room temperature after which time another 3.95 g (29.7 mmol) of AlCl3 was added. After stirring for 10 minutes, the reaction was quenched carefully with 0.1 M HCl (˜50 mL). After concentration of the organic solvent, the crude reaction mixture was partitioned between 1M HCl and EtOAc (70 mL each). The aqueous layer was back extracted 1× EtOAc. The combined organic layers were dried over MgSO4 and concentrated. The sub-title product (1.45 g) was obtained after purification by silica gel chromatography (0 to 35% EtOAc in Hexanes). MS: ESI (positive): 226 (M+H).