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Alkynol
Release time：2019-10-09 17:47:49
Product introduction: Alkynol compounds are important organic synthesis intermediates in the fields of medicine, pesticides, material synthesis and metal carbonation and hydrogenation.
Existing processes and problems: the synthesis of existing acetylenic alcohol compounds is mainly obtained by reacting an acetylene gas with an ethyl Grignard reagent to obtain an alkyne Grignard reagent, and then reacting with the corresponding aldehyde or ketone to deprotonate in an alkaline solution. (usually using NH4Cl). This method requires the acetylene gas to be dissolved in the reaction raw material at a very low temperature. In addition, an aryl-substituted terminal alkyne can be reacted with an ethyl Grignard reagent to obtain an alkyne Grignard reagent, which is obtained by a similar subsequent reaction, but the raw material cost is high and cannot be applied to the aryl substituent. A raw material substituted with a phenyl group, a furyl group, a pyridyl group or an alkenyl group. For this purpose, other synthetic routes are usually employed, in which a catalyst such as Pd/Cu is required.
The present technology and characteristics: the technology adopts a plurality of microreactors in series mode, using acetylene gas as an alkyne-based raw material, and reacting with a common common Grignard reagent to obtain an alkyne-based Grignard reagent without low-temperature operation; and then in a microreactor The corresponding acetylenic alcohol compound can be obtained by reacting with the corresponding aldehyde or ketone. Its features include:
Effectively increase the yield and selectivity of the product;
This kind of reaction can be carried out at 0 oC and normal temperature, avoiding multiple cooling and temperature rising operations;
The reaction time can be greatly shortened, and the conventional Grignard reaction slow dropping operation is broken.
R1: alkyl CnH2n+1 (n = 0 ~ 5) or an aromatic group, the aryl group being a methoxyphenyl group, a bromophenyl group, a chlorophenyl group, a fluorophenyl group, a trimethoxyphenyl group or a styryl group;
R2: an alkyl group CnH2n+1 (n = 1 to 5) or an aryl group, and the aryl group is a methoxyphenyl group, a bromophenyl group, a chlorophenyl group, a fluorophenyl group, a trimethoxyphenyl group or a styryl group.
| Preparation of propargyl alcohol compounds by Grignard exchange | Yield/% | time/min | temperature/oC |
| Microstructure reactor | 87-98 | 0.2 | 0-25 |
| Batch reactor | 61-84 | ~360 | -40 |