- Novel synthesis method of clean and safe photoinitiator (2,4,6-trimethylbenzoyldiphenyl-diphenylphosphine oxide)
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The invention relates to the technical field of synthesis of photoinitiators, in particular to a novel synthesis method of a clean and safe photoinitiator (2,4,6-trimethylbenzoyldiphenyl-diphenylphosphine oxide). The method includes the steps of evenly mixing anhydrous alcohol with N-methylimidazole at the room temperature, raising the temperature to 30-50%, controlling the temperature, dropwise adding diphenylphosphine oxide, raising the temperature to 50-100 DEG C, conducting the constant-temperature reaction for 2-3 h, conducting standing and layering to take supernatant liquid for decompressing and distilling to obtain diphenyl alkoxylphosphine, making the diphenyl alkoxylphosphine start to react with 2,4,6-trimethylbenzoyldiphenyl chloride at the controlled temperature of 50 DEG C under the vacuum condition of -0.098 Mpa, raising the temperature by 10 DEG C every 20 minutes until the temperature is raised to 90 DEG C, conducting the constant-temperature reaction for 4-8 h, and adding 50% ethyl alcohol crystals to obtain a target product. The produced byproduct is subjected to vacuum removal and then enters a tail gas recovery system to be recovered through two stages of condensation. The synthesis method is simple in step, safe, clean, low in running cost and high in byproduct recovery rate.
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Paragraph 0045; 0046
(2019/06/12)
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- Efficient method for the preparation of carboxylic acid alkyl esters or alkyl phenyl ethers by a new-type of oxidation-reduction condensation using 2,6-dimethyl-1,4-benzoquinone and alkoxydiphenylphosphines
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A new-type of oxidation-reduction condensation proceeded smoothly to afford carboxylic acid alkyl esters or alkyl phenyl ethers in good to high yields by combined use of alkoxydiphenylphosphines (1) having primary, bulky secondary or tertiary alkoxy groups, a mild quinone-type oxidant such as 2,6-dimethyl-1,4-benzoquinone (DMBQ) and carboxylic acids or phenols. Generally, alkoxydiphenylphosphines were prepared easily from chlorodiphenylphosphine (2) and alcohols in the presence of pyridine, and were isolated by distillation. On the other hand, the phosphines 1 were also prepared in situ from N,N-dimethylaminodiphenylphosphine (3a) and primary or secondary alcohols while primary, bulky secondary or tertiary alkoxydiphenylphosphines were alternatively formed in situ by adding 2 to the "BuLi-treated alcohols in order to perform the above reactions by a one-pot procedure from alcohols and nucleophiles. The reaction of thus formed 1, DMBQ and carboxylic acids or phenols afforded the corresponding alkylated products, including hindered secondary and tertiary alkylated ones, in good to high yields at room temperature. In the case of using chiral secondary alcohols, the corresponding carboxylic acid alkyl esters were obtained as well in high yields with perfect inversion of stereochemistry by SN2 replacement.
- Shintou, Taichi,Kikuchi, Wataru,Mukaiyama, Teruaki
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p. 1645 - 1667
(2007/10/03)
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