Methylparaben → Benzoic acid, 4-[(tetrahydro-2H-pyran-2-yl)oxy]-, methyl ester

HRID 892708ノート

反応式

HRID 892708 の反応式
[OH:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][CH:3]=1.[O:12]1[CH:17]=[CH:16][CH2:15][CH2:14][CH2:13]1>S(=O)(=O)(O)O>[O:12]1[CH2:17][CH2:16][CH2:15][CH2:14][CH:13]1[O:1][C:2]1[CH:3]=[CH:4][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:10][CH:11]=1

参加物

4

反応物 2

HCID 7456MethylparabenHCID 80803,4-dihydro-2H-pyran

生成物 1

HCID 11770459Benzoic acid, 4-[(tetrahydro-2H-pyran-2-yl)oxy]-, methyl ester

試薬・触媒・溶媒 1

HCID 1118Sulfuric Acid触媒

実験手順

To a solution of 0.64 mL (2 mmol) of 1-(2-trimethylsiloxyethoxy)-1-trimethylsiloxy-2-methyl-1-propene, 0.55 mL of tetrabutylammonium biacetate (0.04M in THF), and 0.06 mL of bis(dimethylamino)methylsilane in 40 mL of THF was added dropwise a solution of 20 g (72.5 mmol) of 4-tetrahydropyranyloxybenzyl methacrylate (purified by passing over a column of basic alumina in hexane solution, followed by evaporation of the hexane under reduced pressure) in 30 mL of THF. When the exothermic polymerization was finished, and the temperature had returned to room temperature, the reaction mixture was poured into methanol. Filtration gave 19 g of poly(4-tetrahydropyranyloxybenzyl methacrylate). GPD: Mn =9390, Mw =11,500, MwMn =1.23. DSC: Tg =62.3° C., with a decomposition endotherm at 250.5° C. TGA: rapid loss of 24.74% of weight at 248.1° C. The monomer was prepared from methyl 4-hydroxybenzoate by reaction with an excess of 3,4-dihydro-2H-pyran in the presence of sulfuric acid catalyst to give methyl 4-(2-tetrahydropyranyloxy)benzoate, which was then reduced with lithium aluminum hydride in THF solution to give 4-(2-tetrahydropyranyloxy)benzyl alcohol. Esterification with methacrylyl chloride and triethylamine in dichloromethane solution gave 4-tetrahydropyranyloxybenzyl methacrylate, m.p. 36° C.

後処理

  1. customTg =62.3° C.
  2. customat 250.5° C
  3. customat 248.1° C

出典と根拠

ORDレコード
ord-78f5c880dc384d258f8fa67ba0f2a5a7
出典データセット
uspto-grants-1992_06
特許番号
US05120633

反応ノート

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