tert-Butyl 4-oxopiperidine-1-carboxylate → 1-tert-butoxycarbonyl-4-{4-[1 (S)-(4-bromophenyl)-ethyl]-3(R)-methylpiperazin-1-yl}-piperidine
Reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]([N:10]2[CH2:15][CH2:14][NH:13][CH2:12][CH:11]2[CH3:16])[CH3:9])=[CH:4][CH:3]=1.[C:17]([N:24]1[CH2:29][CH2:28][C:27](=O)[CH2:26][CH2:25]1)([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>C(Cl)Cl>[C:20]([O:19][C:17]([N:24]1[CH2:29][CH2:28][CH:27]([N:13]2[CH2:14][CH2:15][N:10]([C@H:8]([C:5]3[CH:6]=[CH:7][C:2]([Br:1])=[CH:3][CH:4]=3)[CH3:9])[C@H:11]([CH3:16])[CH2:12]2)[CH2:26][CH2:25]1)=[O:18])([CH3:23])([CH3:21])[CH3:22]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
The product of step 4 was stirred for 20 h. at RT with N-Boc-4-piperidinone (4.32 g), HOAC (1.15 ml), CH2Cl2 (80 ml) and sodium triacetoxy-borohydride (NaBH(OAc)3) (8.3 g). Thereafter the reaction was quenched with excess aqueous Na2CO3 solution slowly and stirred for 0.5 h. The organic layer was separated and filtered through a pad of silca gel, washing with 10:1 CH2Cl2-Et2O to elute all of the product. The filtate was evaporated and dissolved in Et2O (100 ml). To this was added dropwise a 4M solution of HCl in 1,4-dioxane (10 ml). The solids were collected, washed with Et2O, and stirred with CH2Cl2 and excess aqueous NaOH. The organic phase was dried over K2CO3 and evaporated to obtain 1-tert-butoxycarbonyl-4-{4-[1 (S)-(4-bromophenyl)-ethyl]-3(R)-methylpiperazin-1-yl}-piperidine (5.45 g).
Workup
- customThereafter the reaction was quenched with excess aqueous Na2CO3 solution slowly
- customThe organic layer was separated
- filtrationfiltered through a pad of silca gel
- washwashing with 10:1 CH2Cl2-Et2O
- washto elute all of the product
- customThe filtate was evaporated
- dissolutiondissolved in Et2O (100 ml)
- additionTo this was added dropwise a 4M solution of HCl in 1,4-dioxane (10 ml)
- customThe solids were collected
- washwashed with Et2O
- stirringstirred with CH2Cl2 and excess aqueous NaOH
- dry with materialThe organic phase was dried over K2CO3
- customevaporated
Sources & evidence
- ORD record
- ord-affb486a76dc4bfc97e8478d0ef6fcac
- Source dataset
- uspto-grants-2008_03
- Patent number
- US07345042B2
Reaction notes
Loading…