GB529081A - Improvements in coumaranes and chromanes and method of producing the same - Google Patents

Abstract

529,081. Coumaranes and chromanes. MINNESOTA, REGENTS OF THE UNIVERSITY OF. May 22, 1939, No. 15116. Convention date, May 31, 1938. [Class 2 (iii)] Coumaranes and chromanes are produced from hydroquinone compounds by reacting at an elevated temperature hydroquinone compounds having vacant at least one position ortho to the hydroxyl group with substituted or unsubstituted allylic bromide or chlorides without the addition of a catalyst. In examples (1) trimethyl-hydroquinone is reacted with allyl bromide in a sealed tube at 110‹ C. to give 2:4:6:7-tetramethyl-5-hydroxy coumarane. (2) The substitution of gamma-gamma dissubstituted alkylic halides having the general formulawhere Hal indicates a halogen atom, and R 1 and R 2 are alkyl radicals for gamma-unsubstituted allylic halides results in a six. membered chromane ring instead of a five membered coumarane ring. This is exemplified by the reaction of trimethyl hydroquinone with gamma-gamma dimethyl allyl bromide in a sealed tube at 140‹ C., for four hours to give 2:2:5:7:8 -pentamethyl - 6 - hydroxy chromane. (3) Phytyl bromide and trimethyl-hydroquinone are reacted in a sealed tube at 125‹ C. The Specification as open to inspection under Sect. 91 includes also the carrying out of the reaction in the presence of a catalyst, and as an example of the use of a catalyst there is reacted together trimethyl-hydroquinone in the presence of a zinc chloride catalyst. It is also stated that examples (1), (2), and (3) above may also be carried out in the presence of a catalyst. This subject-matter does not appear in the Specification as accepted. Specifications 526,884 and 527,396 are referred to.