4-Methylmorpholine → Boc-Lys(Ac) aminocyanobenzothiazole

HRID 471464Notes

Reaction equation

HRID 471464 reaction equation
[CH3:1][C:2]([NH:4][CH2:5][CH2:6][CH2:7][CH2:8][C@H:9]([NH:13][C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[C:10]([OH:12])=[O:11])=[O:3].C[N:22]1CCOCC1.C(OC(Cl)=O)C(C)C.N[C:37]1[CH:47]=[CH:46][C:40]2[N:41]=[C:42]([C:44]#[N:45])[S:43][C:39]=2[CH:38]=1>C1COCC1>[NH:13]([C:14]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[C@H:9]([C:10]([OH:12])=[O:11])[CH2:8][CH2:7][CH2:6][CH2:5][NH:4][C:2]([CH3:1])=[O:3].[NH2:22][C:46]1[C:40]2[N:41]=[C:42]([C:44]#[N:45])[S:43][C:39]=2[CH:38]=[CH:37][CH:47]=1

Participants

6

Reactant 4

HCID 79724-MethylmorpholineHCID 62365Isobutyl chloroformateHCID 7016049Boc-Lys(Ac)-OHHCID 141571126-Amino-2-cyanobenzothiazole

Product 1

HCID 131731143Boc-Lys(Ac) aminocyanobenzothiazoleYield 93.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred solution of Boc-Lys-(Ac)—OH (20.5 g, 71 mmol) in dry THF (410 mL), N-methylmorpholine (7.8 mL, 71 mmol) was added under an atmosphere of N2. The reaction vessel was cooled to 4° C. for 20 minutes, at which time isobutylchloroformate (9.3 mL, 71 mmol) was added drop-wise. The reaction was allowed to stir in an ice bath for approximately 60 minutes, at which time 6-amino-2-cyanobenzothiazole (10 g, 57 mM) was added. The reaction was allowed to stir for approximately 30 minutes in the ice bath, removed, and the reaction mixture allowed to reach room temperature overnight. The reaction was then filtered through a Buchner funnel, and the filtrate concentrated to a solid foam. This solid foam was dissolved in dichloromethane (1 L) and washed 2× with NaHCO3 (sat. aq., 300 mL). The organic phase was dried over Na2SO4, filtered, and concentrated to provide a solid foam. This solid foam was then purified by silica gel chromatography with a gradient of heptanes/ethyl acetate (Teac) (40% Teac to 100% Teac step gradient over 80 minutes) to provide 24.7 g of Boc-Lys(Ac)-aminocyanobenzothiazole as a foamy solid.

Workup

  1. additionwas added drop-wise
  2. additionwas added
  3. customremoved
  4. filtrationThe reaction was then filtered through a Buchner funnel
  5. concentrationthe filtrate concentrated to a solid foam
  6. dissolutionThis solid foam was dissolved in dichloromethane (1 L)
  7. washwashed 2× with NaHCO3 (sat. aq., 300 mL)
  8. dry with materialThe organic phase was dried over Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated
  11. customto provide a solid foam
  12. customThis solid foam was then purified by silica gel chromatography with a gradient of heptanes/ethyl acetate (Teac) (40% Teac to 100% Teac step gradient over 80 minutes)

Sources & evidence

ORD record
ord-3b48c9f558304152bfff4468a8264d8d
Source dataset
uspto-grants-2014_01
Patent number
US08632992B2

Reaction notes

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