3,4-DIHYDRO-2H-BENZOPYRAN DERIVATIVE AND ITS PREPARATION

• Main Authors: FUJITA YOSHIJI, SHIONO MANZOU, NISHIDA TAKUJI
• Format: Patent
• Language: English
• Published: 06.06.1984
• 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

NEW MATERIAL:The compound of formula I [R is H or alkyl; R and R are H, alkyl, alkoxy or together form -CH=CH-CH=CH-; R is H or protecting group; A is (CH2)n (n is >=1) or phenylene]. EXAMPLE:Di[2-( 3,4-dihydro-6-hydroxy-2,5,7,8-tetramethyl-2H-benzopyranyl )- ethyl] succinate. USE:Antioxidant for organic material sensitive to oxygen (e.g. oils and fats, rubber product, plastics, etc.). It has higher effect than vitamin E. PROCESS:The compound of formula I is prepared by reacting the 2-substituted ethyl alcohol of formula II (R is H or protecting group) with the dicarboxylic acid of formula III under the ester-synthesis reaction condition. The starting compound of formula II can be obtained by reacting the hydroquinone (derivative) of formula IV with 4-methyl-5,6-dihydro-2H-pyran in the presence of a Lewis acid.