108-55-4, Dihydro-2H-pyran-2,6(3H)-dione is a Tetrahydropyrans compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated
Charge 250 g of anhydrous AlCl3 (1.87 moles) to a 2 L 3-neck round bottom flask, add 300 mL fluorobenzene (307.5 g; 3.2 moles) and cool the mixture in an ice bath to 5C. Add a hazy suspension of 100 g glutaric anhydride (0.86 mole) in 400 mL fluorobenzene (4.3 moles) through an addition funnel over a period of 45 min., and maintain the temperature below 12C. Warm the reaction mixture to ambient temperature gradually and agitate at r.t. for about 90 min.; check for completion by NMR. Cool the reaction mixture to 0 to 5C, then add a cold aqueous solution (700 mL) of 1 N HCl carefully to the mixture to destroy any unreacted AlCl3, keeping the temperature of the mixture below 20C during the early part of the acid addition, and below 40C for the rest of the time. Pour the entire mixture into a 2 L 1:1 mixture of water and ice (v/w) to precipitate out crude products, filter the white suspension and wash well with water. Add the white residue to 3 L of aqueous saturated solution (~5%) of NaHCO3, heat the basic mixture on a steam bath for one hour and filter the batch while hot through a thin pad of celite. Cool the filtrate to r.t., add about 320 mL of concentrated HCl dropwise into the filtrate to pH 1 to crystallize out products, and agitate the white suspension in an ice bath for 30 min. Filter the batch, wash the wet cake with ice cold water and dry in a vacuum oven at 50C for 16 h to obtain 143.2 g of 4-(4-fluorobenzoyl)-butyric acid; m.p. 141 to 142C, isolated yield: 79.3%.
108-55-4, As the paragraph descriping shows that 108-55-4 is playing an increasingly important role.
Reference£º
Patent; SCHERING CORPORATION; EP1137634; (2005); B1;,
Tetrahydropyran – Wikipedia
Tetrahydropyran – an overview | ScienceDirect Topics