Preparation method of 4-ethyl phenyl isothiocyanate_Kain Industrial Additive

Background and overview^[1]

4-Ethyl phenyl isothiocyanate can be used as an intermediate in pharmaceutical synthesis, such as the preparation of thiazolidine compounds. Thiazolidines are widely found in various natural products and have good biological activity. Among them, 2- Iminothiazolidin-4-one is the basic structural unit of many natural products, bioactive molecules and pharmaceutical molecules. Compounds with 2-iminothiazolidin-4-one structural units have a variety of physiological activities, such as anticancer activity and anticonvulsant activity, and can be used to prepare receptor inhibitors to inhibit the growth of human liver cancer cells and inhibit human colon cancer cells proliferation, etc. Based on this, 2-iminothiazolidine-4-one compounds have attracted widespread attention. If 4-ethyl phenyl isothiocyanate is inhaled, move the patient to fresh air; if skin contact occurs, remove contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical attention if you feel unwell.

Preparation^[1]

4-Ethyl phenylisothiocyanate can be used as a pharmaceutical synthesis intermediate. For example, prepare the following compounds:

Add 0.1mmol benzylamine, 0.1mmol 4-ethyl phenyl isothiocyanate, 0.3mmol 2-ethyl bromoacetate, 0.4mmol sodium hydroxide, and 1ml acetonitrile into the reaction tube, and illuminate it with a 465nm light source , stir and react for 12 hours. After the reaction is completed, it is separated and purified by column chromatography. The volume ratio of petroleum ether and ethyl acetate in the column chromatography eluent is 5:1. The purified target product is obtained with a yield of 90% and a purity of 99.8%.

Characterize the structure of the obtained product. The structural characterization data are as follows:

1HNMR (400MHz, CDCl3): δ=7.51-7.49 (d, J=7.1Hz, 2H), δ=7.32-7.24 (m, 3H), δ=7.16-7.14 (d, J=8.1Hz, 2H), δ=6.88-6.86 (d, J=7.9Hz, 2H), δ=4.99 (s, 2H), δ=3.72 (s, 2H), δ=2.64-2.59 (q, J=7.6Hz, 2H), δ=1.24-1.20 (t, J=7.6Hz, 3H).

13CNMR (100MHz, CDCl3): δ=171.6, 153.5, 145.5, 140.6, 136.1, 129.1, 128.6, 128.5, 127.9, 120.9, 46.2, 32.7, 28.4, 15.6.

MS (EI, 70eV): m/z (%) = 310.1 (M+), 268.1, 236.2, 207.1, 165.1, 148.1, 131.1, 105.1, 91.1, 65.1.

Main reference materials

[1] CN201711249923.0 Preparation method of 2-iminothiazolidine-4-one compounds