Benzoxazole derivative preparation method

• Main Author: NIU YUBO
• Format: Patent
• Language: English
• Published: 10.02.2016
• Subjects: CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

The invention relates to a benzoxazole derivative preparation method, belongs to the technical field of medicine, and particularly relates to a benzoxazole derivative preparation method. The invention provides a benzoxazole derivative preparation method with characteristics of simple operation and environmental protection and suitable for rapid benzoxazole derivative preparation. The preparation method comprises: (1) adding methyl L-tyrosinate to a reaction container, adding 0.08 g (1.28 mmol) of sodium sulfate, stirring, and standing for 40 min; (2) carrying out a reaction to obtain -3-4-hydroxy-3-nitrophenyl-2-trifluoroacetyl amino methyl propionate, and carrying out heating reflux on the compound for 20 h in 3 M HCl/MeOH; (3) removing trifluoroacetyl protection to obtain S-2-amino-3-4-hydroxy-3-nitrophenyl methyl propionate hydrochloride, wherein the yield is 90%; (4) protecting the amino group with Boc, and generating diethoxy phosphono benzoxazole 6 with an intermediate 11, wherein the yield is about 45%; and (5) carrying out butt joint of the compound 6 and an intermediate aldehyde 12 to obtain a compound 7, carrying out double bond reduction with Pt to obtain a compound 8, and removing the Boc so as to obtain the amino acid methyl ester 9.