Hydrochloric Acid → HCID 178497600, compound

HRID 2370312Notes

Reaction equation

HRID 2370312 reaction equation
Cl.[NH:2]1[C:10]2[CH:9]=[CH:8][CH:7]=[C:6]([C:11]([O:13][CH3:14])=[O:12])[C:5]=2[CH:4]=[CH:3]1.[N:15]([O-])=O.[Na+].[OH2:19]>>[CH:3]([C:4]1[C:5]2[C:6]([C:11]([O:13][CH3:14])=[O:12])=[CH:7][CH:8]=[CH:9][C:10]=2[NH:2][N:15]=1)=[O:19]

Participants

5

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 2733668methyl 1H-indole-4-carboxylateHCID 23668193Sodium Nitrite

Product 1

HCID 178497600HCID 178497600, compoundYield 35%

Procedure

Aqueous HCl (56.0 mL of 6N solution in water, 0.33 mol) was added dropwise over 1 hour to a stirring suspension of methyl 1H-indole-4-carboxylate (5.0 g, 28.5 mmol) in a solution of sodium nitrite (24.0 g, 0.34 mol) in water (500 mL) at ambient temperature. The mixture was stirred overnight at ambient temperature, and then extracted with ethyl acetate (5×300 mL). The combined organic layers were washed with water (2×300 mL), brine (200 mL), and dried (Na2SO4). The organics were concentrated under reduced pressure until precipitation was observed. After cooling in a dry ice bath the precipitate was collected by filtration, washed with cold ethyl acetate (50 mL), and hexanes (100 mL) and dried (Na2SO4) to afford methyl 3-formyl-1H-indazole-4-carboxylate (B1, 2.1 g, 35%) as a yellow powder: 1H NMR (300 MHz, DMSO-d6) δ 10.33 (s, 1H), 7.92 (d, J=8.1 Hz, 1H), 7.67 (d, J=7.2 Hz, 1H), 7.58 (t, J=7.2 Hz 1H), 3.96 (s, 3H); MS (ESI+) m/z 205 (M+H).

Workup

  1. extractionextracted with ethyl acetate (5×300 mL)
  2. washThe combined organic layers were washed with water (2×300 mL), brine (200 mL)
  3. dry with materialdried (Na2SO4)
  4. concentrationThe organics were concentrated under reduced pressure until precipitation
  5. temperatureAfter cooling in a dry ice bath the precipitate
  6. filtrationwas collected by filtration
  7. washwashed with cold ethyl acetate (50 mL), and hexanes (100 mL)
  8. dry with materialdried (Na2SO4)

Sources & evidence

ORD record
ord-4b622ca7562a4161ae23d51bdf46317d
Source dataset
uspto-grants-2014_04
Patent number
US08710047B2

Reaction notes

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