802-71-1Relevant academic research and scientific papers
Preparation method of halcinonide and derivative thereof
-
Paragraph 0116; 0120; 0127, (2018/03/26)
The invention provides a preparation method of halcinonide and a derivative thereof. The method comprises the following steps: taking hydrocortisone acetate as a raw material, performing dehydration and then epoxidation on the raw material, performing ring opening, performing hydrolysis and chlorination, and then performing oxidation and ketalization, so as to obtain halcinonide; or performing dehydration and then epoxidation on the raw material, performing ring opening, performing hydrolysis, and then performing oxidation and ketalization, so as to obtain 9-fluoro-16a,17-(isopropylidenedioxy)corticosterone. In ring opening fluorination unit reaction, safe and mild reaction environment is selected, a fluorizating agent with low concentration is used as a reaction reagent, the reaction rate is effectively controlled, the production of side reaction products is restrained, and the product quality and yield are greatly improved. Moreover, in 16, 17-ketalization unit reaction, an acid catalyst which is low in toxicity and easy to control is adopted to replace boron trifluoride with high toxicity to perform catalysis, and the catalytic effect is effectively improved.
Synthesis of 17-(2-Methoxy-3-oxazolin-4-yl)-, 17-(3-Oxazolin-4-yl)-, and 17-(2-Oxazolin-4-ylidene)-Substituted Steroids and Their Use as Precursors of Corticosteroids
Leusen, Daan van,Batist, Jacobus N. M.,Lei, Jia,Echten, Erik van,Brouwer, Antoon C.,Leusen, Albert M. van
, p. 5650 - 5657 (2007/10/02)
17-(Isocyanotosylmethylene)steroids 4 are useful intermediates in the conversion of 17-oxosteroids into 17-(hydroxyacetyl)steroids.The 21-CH2OH group is effectively introduced by a base-mediated reaction of compounds 4 with formaldehyde and MeOH to give 17-(2-methoxy-3-oxazolin-4-yl)derivatives 12, which by acid hydrolysis give 17-(hydroxyacetyl)steroids 10 and 16 in high yields.Partial hydrolysis of the same oxazoline derivatives 12 provides the 17-(hydroxyacetyl) cortico side chain of 13 equipped with a formyl-protected hydroxy group. 3-Oxazolinyl and 2-oxazolinylidene steroid derivatives 19, 20, and 21, without a 2-methoxy substituent, are discussed as alternatives of 12.
A NOVEL METHOD TO BUILD ACETYL AND HYDROXYACETYL SIDE-CHAINS IN 17-OXOSTEROIDS
Leusen, Daan van,Leusen, Albert M. van
, p. 2581 - 2584 (2007/10/02)
Nine examples are given of the title process.
