p-Toluenesulfonic acid monohydrate → 6-Cyclopropylpicolinaldehyde

HRID 1432418Notes

Reaction equation

HRID 1432418 reaction equation
[CH:1]1([C:4]2[CH:9]=[CH:8][CH:7]=[C:6]([CH:10]3OCC[O:11]3)[N:5]=2)[CH2:3][CH2:2]1.S(O)(C1C=CC(C)=CC=1)(=O)=O.O>CC(C)=O.O>[CH:1]1([C:4]2[N:5]=[C:6]([CH:10]=[O:11])[CH:7]=[CH:8][CH:9]=2)[CH2:3][CH2:2]1

Participants

5

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 193617732-Cyclopropyl-6-(1,3-dioxolan-2-yl)pyridine

Product 1

HCID 193617216-CyclopropylpicolinaldehydeYield 94%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

A mixture of 2-cyclopropyl-6-[1,3]dioxolan-2-yl-pyridine (0.9 g, see subpart (b) above) and a catalytic amount of TsOH hydrate in a mixture of acetone (10 mL) and water (2 mL) was heated to reflux overnight until most of the starting materials were consumed according to TLC. It was then cooled down to room temperature and concentrated. The residue was dissolved in diethyl ether and washed with saturated sodium carbonate, and then water, and then dried over MgSO4 and concentrated. The concentrate was purified on silica gel column with 100% CH2Cl2 to yield 6-cyclopropyl-pyridine-2-carbaldehyde as a bright liquid (0.65 g, 94%). 1H NMR (CDCl3, 300 MHz), δ 9.90 (s, 1H), 7.58(m, 2H), 7.23 (m, 1H), 2.01 (m, 1H), 1.02-0.92 (m, 4H).

Workup

  1. temperaturewas heated
  2. temperatureto reflux overnight until most of the starting materials
  3. customwere consumed
  4. concentrationconcentrated
  5. dissolutionThe residue was dissolved in diethyl ether
  6. washwashed with saturated sodium carbonate
  7. dry with materialwater, and then dried over MgSO4
  8. concentrationconcentrated
  9. customThe concentrate was purified on silica gel column with 100% CH2Cl2

Sources & evidence

ORD record
ord-fa3064d84f6047c0beb9800f2148983a
Source dataset
uspto-grants-2009_11
Patent number
US07612094B2

Reaction notes

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