反応 #1833

反応方程式

toluene

paraformaldehyde

Methylmagnesium chloride

p-cresol

→

product

収率 18.0%

2-Hydroxy-5-methylbenzaldehyde

収率 18.0%

溶媒

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

反応条件

後処理

1. 1
   その他the exothermic reaction
2. 2
   温度The reaction mixture was heated
3. 3
   温度at reflux for 18 hours
4. 4
   温度cooled
5. 5
   洗浄washed with 200 mL of 2N aqueous hydrochloric acid and 200 mL of water
6. 6
   その他The organic layer was removed
7. 7
   ろ過filtered through Celite
8. 8
   乾燥dried over magnesium sulfate
9. 9
   ろ過filtered
10. 10
    その他solvents removed under vacuum
11. 11
    その他Crystallization of the crude residue from cold hexanes

実験手順

Methylmagnesium chloride solution in tetrahydrofuran (100 mL, 3.0M, 300 mmol) at room temperature was treated dropwise over 30 minutes with a solution of 32.3 g (300 mmol) of p-cresol in 30 mL of tetrahydrofuran. An additional 70 mL of tetrahydrofuran was added to moderate the exothermic reaction. The mixture was aged at room temperature for 2 hours then treated with 400 mL of toluene, 41mg of 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone and 23 g of paraformaldehyde. The reaction mixture was heated at reflux for 18 hours, then cooled and washed with 200 mL of 2N aqueous hydrochloric acid and 200 mL of water. The organic layer was removed, filtered through Celite, dried over magnesium sulfate, filtered and solvents removed under vacuum. Crystallization of the crude residue from cold hexanes gave 7.4 g (54 mmol, 18%) of the product. The mother liquors were further purified by column chromatography on silica gel, eluting with methylene chloride, to give an additional 17.5 g (128 mmol, 43%) of the product. 1H NMR (200 MHz,CDCl3): 2.33 (s,3H), 6.89 (d,10 Hz,1H), 7.33 (m,2H), 9.83 (s,1H), 10.80 (s,1H).

出典