Toluene → Benzyl 5,6-dihydropyridine-1(2H)-carboxylate

HRID 1389850Notes

Reaction equation

HRID 1389850 reaction equation
[NH:1]1[CH2:6][CH2:5][CH:4]=[CH:3][CH2:2]1.C(=O)(O)[O-].[Na+].Cl[C:13]([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14].C1(C)C=CC=CC=1>C1C=CC=CC=1>[C:13]([N:1]1[CH2:6][CH2:5][CH:4]=[CH:3][CH2:2]1)([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14]

Participants

6

Reactant 4

HCID 1140TolueneHCID 10387Benzyl chloroformateHCID 127501,2,3,6-TetrahydropyridineHCID 516892Sodium Bicarbonate

Product 1

HCID 11458613Benzyl 5,6-dihydropyridine-1(2H)-carboxylate

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

83.1 g (1 mol) of 1,2,5,6-tetrahydropyridine are dissolved in 300 ml of benzene. 83 g of sodium bicarbonate are introduced into this solution and the mixture is cooled to 0° under a nitrogen atmosphere and, at this temperature, treated dropwise in the course of one hour with 332 ml of a 50% strength solution of benzyl chloroformate in toluene (1 mol). The reaction mixture is stirred at 0° for a further 21/2 hours and then poured into 1.5 liters of ice-water. The benzene phase is separated off and the aqueous phase is extracted by shaking 3 times with 250 ml of methylene chloride; subsequently the combined organic phases are washed with 1 N hydrochloric acid and then with a saturated solution of sodium chloride, dried over sodium sulphate and evaporated under a water pump vacuum. The oily residue is distilled under a high vacuum and gives 1-carbobenzyloxy-1,2,5,6-tetrahydropyridine with a boiling point of 102°-113°/0.01 mm Hg.

Workup

  1. temperaturethe mixture is cooled to 0° under a nitrogen atmosphere and, at this temperature
  2. customThe benzene phase is separated off
  3. extractionthe aqueous phase is extracted
  4. stirringby shaking 3 times with 250 ml of methylene chloride
  5. washsubsequently the combined organic phases are washed with 1 N hydrochloric acid
  6. dry with materialwith a saturated solution of sodium chloride, dried over sodium sulphate
  7. customevaporated under a water pump vacuum
  8. distillationThe oily residue is distilled under a high vacuum

Sources & evidence

ORD record
ord-0dc2d2580cdd41b8a49f294d60e91167
Source dataset
uspto-grants-1981_01
Patent number
US04246269

Reaction notes

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