Methyl chloroformate → Methyl 2,3-dihydro-1H-indole-1-carboxylate

HRID 234494Notes

Reaction equation

HRID 234494 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][CH2:2]1.Cl[C:11]([O:13][CH3:14])=[O:12]>N1C=CC=CC=1.C(Cl)Cl>[CH3:14][O:13][C:11]([N:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][CH2:2]1)=[O:12]

Participants

5

Reactant 2

HCID 6586Methyl chloroformate2×HCID 10328Indoline

Product 1

HCID 690083Methyl 2,3-dihydro-1H-indole-1-carboxylateYield 56%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution of 10 g of indoline in 10 ml of pyridine is cooled to 0° C., a solution of 7.9 g of methyl chloroformate in 10 ml of DCM is added dropwise and the mixture is stirred for 1 hour at 0° C. A further solution of 7.9 g of methyl chloroformate in 10 ml of DCM is then added and the reaction mixture is concentrated under vacuum. The residue is taken up with water and extracted with AcOEt, the organic phase is washed with a 5% solution of potassium hydrogensulfate, with water and with a saturated solution of NaCl and dried over sodium sulfate and the solvent is evaporated off under vacuum to give 8.3 g of the expected product after trituration in a DCM/iso ether mixture and then filtration. M.p.=69°-70° C.

Workup

  1. concentrationthe reaction mixture is concentrated under vacuum
  2. extractionextracted with AcOEt
  3. washthe organic phase is washed with a 5% solution of potassium hydrogensulfate, with water and with a saturated solution of NaCl
  4. dry with materialdried over sodium sulfate
  5. customthe solvent is evaporated off under vacuum

Sources & evidence

ORD record
ord-5ffeee0ad75441119dadfc2823d4048a
Source dataset
uspto-grants-1997_01
Patent number
US05594023

Reaction notes

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