Hydrochloric Acid → 2-Methyl-1-benzothiophene-3-carbaldehyde

HRID 1690306

Reaction equation

HRID 1690306 reaction equation
Cl[Sn](Cl)(Cl)Cl.[CH3:6][C:7]1[S:11][C:10]2[CH:12]=[CH:13][CH:14]=[CH:15][C:9]=2[CH:8]=1.[CH3:16][O:17]C(Cl)Cl.Cl>C(Cl)Cl>[CH3:6][C:7]1[S:11][C:10]2[CH:12]=[CH:13][CH:14]=[CH:15][C:9]=2[C:8]=1[CH:16]=[O:17]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 21004Methane, dichloromethoxy-HCID 24287Tin tetrachlorideHCID 709522-Methylbenzo(b)thiophene

Product 1

HCID 37754672-Methyl-1-benzothiophene-3-carbaldehydeYield 98.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

SnCl4 (20 mL, 67 mmole) was added over 5 min to a stirred solution of 2-methylbenzo[b]thiophene (5.0 g, 33.7 mmole) in CH2Cl2 (75 mL) at 0° C. under argon. After 15 minutes, dichloromethyl methyl ether (3.7 mL, 41 mmole) was added. The reaction became a yellowish colored suspension. The reaction was allowed to warm to RT and stirred for 16 h, then was poured onto ice water (200 mL). The aqueous mixture was acidified with 1.0 N HCl (100 mL) and stirred until the suspension dissolved. The organic phase was separated, dried (MgSO4), and concentrated under vacuum. Purification by flash chromatography on silica gel (10% ethyl acetate/hexane) gave the title compound (5.83 g, 98%) as a white crystalline solid: 1H NMR (400 MHz, CDCl3) δ 10.38 (s, 1 H), 8.61 (d, J=8.1 Hz, 1 H), 7.77 (d, J=8.0 Hz, 1 H), 7.48 (t, 1 H), 7.39 (t, 1 H), 2.93 (s, 3 H).

Workup

  1. additionwas poured onto ice water (200 mL)
  2. stirringstirred until the suspension
  3. dissolutiondissolved
  4. customThe organic phase was separated
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated under vacuum
  7. customPurification by flash chromatography on silica gel (10% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-8ddd07ae60db44fe89e04fa0ad40a655
Source dataset
uspto-grants-2012_04
Patent number
US08153652B2

Linked notes

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