Water → HCID 20430562, compound

HRID 2413126Notes

Reaction equation

HRID 2413126 reaction equation
[CH3:1][C:2]1[S:6][C:5]([CH:7]=O)=[CH:4][CH:3]=1.C[O:10][CH:11](OC)[CH2:12][NH2:13].O.[BH4-].[Na+]>C1C=CC=CC=1>[OH:10][CH:11]1[CH2:12][NH:13][CH2:7][C:5]2[S:6][C:2]([CH3:1])=[CH:3][C:4]1=2

Participants

6

Reactant 4

HCID 962WaterHCID 616635-Methyl-2-thiophenecarboxaldehydeHCID 89728Aminoacetaldehyde dimethyl acetalHCID 4311764Sodium borohydride

Product 1

HCID 20430562HCID 20430562, compoundYield 90%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Conditions

Temperature
60 °C

Procedure

A mixture of 5-methyl-thiophene-2-carboxaldehyde (30 g; 0.237 mole) and aminoacetaldehyde dimethylacetal (27.4 g; 0.261 mole) in benzene (250 ml) is refluxed for 2 hours in a flask provided with a Dean-Stark water separator with overhead condenser. After evaporating to dryness, the residue is dissolved in ethanol (250 ml). Sodium borohydride (13.5 g; 0.355 mole) is added portionwise, and the resulting material is left aside overnight at room temperature. Excess sodium borohydride is destroyed by addition of acetone and the mixture is evaporated to dryness. The residue is taken up into water and extracted with methylene chloride. The organic extracts are dried over sodium sulfate and evaporated to dryness. The resulting residual oil is distilled under reduced pressure; b.p.2 =127° C.; Yield: 90% The resulting N-(5-methyl-2-thienyl)methyl aminoacetaldehyde dimethylacetal is heated at 60° C. for 1 hour in 6N hydrochloric acid (250 ml). After evaporating to dryness, the residue is triturated with acetone. The off-white crystals of the desired hydrochloride are recrystallized from acetonitrile; M.p.=120° C. Overall yield: 61%.

Workup

  1. temperatureis refluxed for 2 hours in a flask
  2. customAfter evaporating to dryness
  3. dissolutionthe residue is dissolved in ethanol (250 ml)
  4. customExcess sodium borohydride is destroyed by addition of acetone
  5. customthe mixture is evaporated to dryness
  6. extractionextracted with methylene chloride
  7. dry with materialThe organic extracts are dried over sodium sulfate
  8. customevaporated to dryness
  9. distillationThe resulting residual oil is distilled under reduced pressure
  10. customb.p.2 =127° C.
  11. customAfter evaporating to dryness
  12. customthe residue is triturated with acetone
  13. customThe off-white crystals of the desired hydrochloride are recrystallized from acetonitrile

Sources & evidence

ORD record
ord-608b10ffead145008b8e1899df351090
Source dataset
uspto-grants-1985_01
Patent number
US04496568

Reaction notes

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