Hydrochloric Acid → Ethyl 1-(benzenesulfonyl)-5-chloro-1H-pyrrolo[3,2-b]pyridine-2-carboxylate

HRID 628339Notes

Reaction equation

HRID 628339 reaction equation
C([Li])CCC.C(NC(C)C)(C)C.[Cl:13][C:14]1[N:19]=[C:18]2[CH:20]=[CH:21][N:22]([S:23]([C:26]3[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=3)(=[O:25])=[O:24])[C:17]2=[CH:16][CH:15]=1.Cl[C:33]([O:35][CH2:36][CH3:37])=[O:34].Cl>C1COCC1>[Cl:13][C:14]1[N:19]=[C:18]2[CH:20]=[C:21]([C:33]([O:35][CH2:36][CH3:37])=[O:34])[N:22]([S:23]([C:26]3[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=3)(=[O:25])=[O:24])[C:17]2=[CH:16][CH:15]=1

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 7912DiisopropylamineHCID 10928Ethyl chloroformateHCID 181764365-Chloro-1-(phenylsulfonyl)-4-azaindoleHCID 178418339Butyllithium

Product 1

HCID 53816579Ethyl 1-(benzenesulfonyl)-5-chloro-1H-pyrrolo[3,2-b]pyridine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

1.6 M n-Butyllithium in hexanes (9.6 mL, 15 mmol) was added to a solution of N,N-diisopropylamine (2.3 mL, 16 mmol) in THF (43 mL) at −78° C. Upon complete addition, the reaction was warmed to 0° C. for 30 minutes and then was re-cooled to −78° C. A solution of 5-chloro-1-(phenylsulfonyl)-1H-pyrrolo[3,2-b]pyridine (3.00 g, 10.2 mmol, from Example 2, Step 1) in THF (8 mL) was added dropwise. After stirring for one hour at −78° C., ethyl chloroformate (1.4 mL, 14 mmol, Alfa Aesar) was added and the reaction was stirred at −78° C. for 2 hours, after which time it was allowed to warm to room temperature. The reaction was poured into dilute HCl and the product was extracted with three portions of ethyl acetate. The combined extracts were dried over sodium sulfate, decanted, and the solvent removed in vacuo. Flash chromatography, eluting with a gradient from 0-30% EtOAc in hexanes afforded product as a yellow solid (2.15 g, 57%).

Workup

  1. additionUpon complete addition
  2. temperaturewas re-cooled to −78° C
  3. stirringthe reaction was stirred at −78° C. for 2 hours
  4. temperatureto warm to room temperature
  5. extractionthe product was extracted with three portions of ethyl acetate
  6. dry with materialThe combined extracts were dried over sodium sulfate
  7. customdecanted
  8. customthe solvent removed in vacuo
  9. washFlash chromatography, eluting with a gradient from 0-30% EtOAc in hexanes afforded product as a yellow solid (2.15 g, 57%)

Sources & evidence

ORD record
ord-f887b83daf0c4314bdabb1a1b85fee33
Source dataset
uspto-grants-2016_04
Patent number
US09309246B2

Reaction notes

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