2-(3-Phthalimidopropylthio)oxazole → 2-(3-Aminopropyl)thiooxazole

HRID 1703591Notes

Reaction equation

HRID 1703591 reaction equation
[H-].NN.C1(=O)[N:8]([CH2:9][CH2:10][CH2:11][S:12][C:13]2[O:14][CH:15]=[CH:16][N:17]=2)C(=O)C2=CC=CC=C12>C(O)C>[NH2:8][CH2:9][CH2:10][CH2:11][S:12][C:13]1[O:14][CH:15]=[CH:16][N:17]=1

Participants

4

Reactant 2

HCID 129234152-(3-Phthalimidopropylthio)oxazoleHCID 86602801Hydrazine monohydride

Product 1

HCID 205501192-(3-Aminopropyl)thiooxazole

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Hydrochloric acid (90 ml) was added to potassium thiocyanate in ethanol (1.8 1.) with stirring. Following filtration from inorganic material, glycollaldehyde (35.9 g) was added and the resulting solution was heated under reflux for 24 hours. Concentration, followed by cooling afforded a white solid, which following recrystallisation from ethanol afforded oxazole-2-thiol (30 g), m.p. 143°-144°. (ii) 3-Bromopropylphthalimide (13.4g) was added to a stirred solution of sodium ethoxide (from 1.15 g sodium) and oxazole-2-thiol (5.1 g) in ethanol (100 ml). The resultant solution was heated under reflux for 2.5 hour and concentrated under reduced pressure. The residue was triturated with water (100 ml) to afford 2-(3-phthalimidopropylthio)oxazole (14 g), m.p. 101°. Recrystallisation from ethanol gave the pure oxazole, m.p. 102°-103°. (iii) Hydrazine hydride (5.3 g) was added carefully to a solution of 2-(3-phthalimidopropylthio)oxazole (10 g) in ethanol (173 ml) with stirring. The solution was then heated under reflux for 25 minutes. After cooling, and filtration from phthalhydrazide, the filtrate was concentrated under reduced pressure and the residue was re-evaporated with ethanol to yield crude 2-(3-aminopropylthio)oxazole. (iv) By the procedure of Example 8(i), 2-(3-aminopropylthio)oxazole (2.1 g) is reacted with 1-nitro-2,2-bis-methylthioethylene (2.0 g) to give 1-nitro-2-methylthio-2-[3-(2-oxazolylthio)propylamino]ethylene (2.1 g) which, on reaction with methylamine by the procedure of Example 8(ii) gives the title product (1.8 g).

Workup

  1. customRecrystallisation from ethanol
  2. customgave the pure oxazole, m.p. 102°-103°
  3. temperatureThe solution was then heated
  4. temperatureunder reflux for 25 minutes
  5. temperatureAfter cooling
  6. filtrationfiltration from phthalhydrazide
  7. concentrationthe filtrate was concentrated under reduced pressure
  8. customthe residue was re-evaporated with ethanol

Sources & evidence

ORD record
ord-8be555c6b7f345c78b1943d73daf902a
Source dataset
uspto-grants-1978_11
Patent number
US04124717

Reaction notes

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