Diethyl Malonate → Diethyl 2-(benzo[d]thiazol-2-yl)malonate

HRID 1507499

Reaction equation

HRID 1507499 reaction equation
[C:1]([O:9][CH2:10][CH3:11])(=[O:8])[CH2:2][C:3]([O:5][CH2:6][CH3:7])=[O:4].[H-].[Na+].Cl[C:15]1[S:16][C:17]2[CH:23]=[CH:22][CH:21]=[CH:20][C:18]=2[N:19]=1>O1CCCC1>[S:16]1[C:17]2[CH:23]=[CH:22][CH:21]=[CH:20][C:18]=2[N:19]=[C:15]1[CH:2]([C:3]([O:5][CH2:6][CH3:7])=[O:4])[C:1]([O:9][CH2:10][CH3:11])=[O:8]

Participants

5

Reactant 3

HCID 7761Diethyl MalonateHCID 119872-ChlorobenzothiazoleHCID 24758Sodium hydride

Product 1

HCID 3922432Diethyl 2-(benzo[d]thiazol-2-yl)malonateYield 96%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Into a solution of 1,3-diethyl propanedioate (280 g, 1.75 mol, 3.00 equiv) in tetrahydrofuran (1000 mL) in a 2000-mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen was added sodium hydride (46.15 g, 1.92 mol, 2.00 equiv) in portions. After stirring for 30 min at room temperature, 2-chloro-1,3-benzothiazole (100.0 g, 589.51 mmol, 1.00 equiv) was added. The reaction mixture was stirred for 20 h at 70° C. in an oil bath, cooled to room temperature, quenched with sat. ammonium chloride (200 mL) and extracted with ethyl acetate (3×500 mL). The combined organic layers were dried over anhydrous sodium sulfate. After filtration and concentration under vacuum, the residue was triturated with 1×500 mL of dichloromethane. The solid was collected by filtration to give 166 g of 1,3-diethyl 2-(1,3-benzothiazol-2-yl)propanedioate as a white solid. MS m/z [M+H]+ (ESI): 294.

Workup

  1. temperaturemaintained with an inert atmosphere of nitrogen
  2. stirringThe reaction mixture was stirred for 20 h at 70° C. in an oil bath
  3. temperaturecooled to room temperature
  4. customquenched with sat. ammonium chloride (200 mL)
  5. extractionextracted with ethyl acetate (3×500 mL)
  6. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
  7. filtrationAfter filtration and concentration under vacuum
  8. customthe residue was triturated with 1×500 mL of dichloromethane
  9. filtrationThe solid was collected by filtration

Sources & evidence

ORD record
ord-c75e61159245429ab951b5f026e1c17e
Source dataset
uspto-grants-2015_12
Patent number
US09221809B2

Linked notes

Loading…