p-Toluenesulfonic acid → 2,2-Dimethyl-2,3-dihydroperimidine

HRID 2372014Notes

Reaction equation

HRID 2372014 reaction equation
[C:1]1([NH2:12])[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][C:9]=2[NH2:11])[CH:4]=[CH:3][CH:2]=1.[C:13]1(C)[CH:18]=CC(S(O)(=O)=O)=C[CH:14]=1.C(=O)([O-])[O-].[Na+].[Na+]>CC(C)=O>[CH3:14][C:13]1([CH3:18])[NH:11][C:9]2[C:10]3[C:5]([CH:6]=[CH:7][CH:8]=2)=[CH:4][CH:3]=[CH:2][C:1]=3[NH:12]1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 10340Sodium CarbonateHCID 680671,8-Diaminonaphthalene

Product 1

HCID 726282,2-Dimethyl-2,3-dihydroperimidineYield 29,096.4%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A solution of 1,8-naphthalene diamine (3.5 g, 22 mmol), distilled as in Example 1, acetone (25 ml) and p-toluene sulfonic acid (10 mg) was prepared and stirred at room temperature for 0.5 hour under a nitrogen atmosphere. The mixture was basified with concentrated sodium carbonate (2 ml) and concentrated to about 5 ml volume. The mixture was diluted with ether (150 ml), washed with water and brine, and dried over potassium carbonate. Concentration gave 3.35 g (77%) 2,3-dihydro-2,2-dimethyl perimidine as a pale pink solid. Recrystallization from hexane-ether gave crystals: mp 114°-115° C.; NMR (CDCl3) 7.07(m, 4H), 6.33(m, 2H), 4.06(bs, 2H), 1.42(s, 6H); IR (KBr) 3364, 3290, 1618, 1595 cm-1.

Workup

  1. customwas prepared
  2. concentrationconcentrated to about 5 ml volume
  3. additionThe mixture was diluted with ether (150 ml)
  4. washwashed with water and brine
  5. dry with materialdried over potassium carbonate
  6. concentrationConcentration

Sources & evidence

ORD record
ord-aa242b532f214f34b2c8a5f5da3ef3a4
Source dataset
uspto-grants-1992_03
Patent number
US05097029

Reaction notes

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