Tag: 108-55-4

With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.108-55-4,Dihydro-2H-pyran-2,6(3H)-dione,as a common compound, the synthetic route is as follows.

To a stirred suspension of aluminum chloride (205.85g, 1. 54MOL) in dichloromethane(500ML) was added a solution of glutaric anhydride (80g, 0. 7MOL) indichloromethane (125ML) at 0C. The reaction mass was stirred for30minutes and fluorobenzene (67.36g, 0. 7MOL) was added to the reactionmass slowly. The reaction was monitored for completion by TLC and thenpoured into ice cold water (2000ML) under stirring and the separatedsolids were collected by filtration. The solids were dissolved in 3%aqueous sodium hydroxide solution (1100ML) and washed withdichloromethane (300ML). The aqueous layer was acidified to give aprecipitate. The solids were filtered and washed with water andvacuum-dried to yield the title product (125g, yield: 85%). LHNMR(CDC13) 8 : 8.027-7. 98 (M, 2H), 7.17-7. 11 (M, 2H), 3.067 (t, 2H), 2.52(t, 2H), 2.14-2. 04 (M, 2H).

As the paragraph descriping shows that 108-55-4 is playing an increasingly important role.

Reference£º
Patent; RANBAXY LABORATORIES LIMITED; WO2004/99132; (2004); A2;,
Tetrahydropyran – Wikipedia
Tetrahydropyran – an overview | ScienceDirect Topics

With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.108-55-4,Dihydro-2H-pyran-2,6(3H)-dione,as a common compound, the synthetic route is as follows.

EXAMPLE 2; Synthesis of Mono-carbonyl butanoic acid 3; To a solution of 2.01 g (5.46 mmol) of curcumin, 1 12 mg (0.92 mmol) of DMAP, and 0.685 g (6 mmol) glutaric anhydride (95%) in 100 ml THF was added 1.33 ml (9.55 mmol) Et3N. The reaction was stirred at reflux under argon overnight. Purified on column chromatography, eluting with CH2Cl2-CH2Cl2)MeOH, 95:5. Yield 84%. NMR 1H (CDCl3), delta (ppm): compound (3),1.97-2.14 (m, 2H); 2.43-2.79 (m, 4H); 3.87-3.95 (d, 6H); 5.83 (s, 2H); 6.45-6.59 (t, 2H); 6.91-7.18 (m, 6H); 7.57-7.65 (d, 2H). 13C NMR (CDCl3), delta (ppm): 19.98; 32.76; 55.82; 101.61 ; 109.86; 1 1 1.36; 1 15.04; 120.95; 121.54; 123.05; 124.16; 127.35; 133.89; 139.38; 139.99; 141.06; 147.03; 148.22; 151.23; 170.98; 177.374; 181.73; 184.65. MS (ESI) calcd. for C26H26O9: 482.48; found: 483.2 [M+H]+. See Robert E. Gawley; Mykhaylo Dukh; Claudia M. Cardona; Stephan H. Jannach; Denise Greathouse. Org. Lett.., Vol. 7, No. 14, 2005.2953-2956.

As the paragraph descriping shows that 108-55-4 is playing an increasingly important role.

Reference£º
Patent; RESEARCH FOUNDATION OF THE CITY UNIVERSITY OF NEW YORK; WO2008/45534; (2008); A2;,
Tetrahydropyran – Wikipedia
Tetrahydropyran – an overview | ScienceDirect Topics

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

General procedure: To a suspension of 48.6 mmol of the proper phenyl derivative and 71.3 mmol of AlCl3 in 60 mL of dry DCM, cooled at 0C, a solution of 32.4 mmol of the proper anhydride in 30 mL of dry DCM was added. The reaction was stirred at rt for 12 h except for the synthesis of 10, which needed only 1 h to proceed to completion. The mixture was then quenched with water and concentrated sulfuric acid; the organic phase was separated from the aqueous one and the solvent evaporated under vacuum. The residue was dissolved in EtOAc, extracted with a 10% NaOH aqueous solution, then acidified with a 1N HCl aqueous solution and re-extracted with EtOAc. Finally the organic phase was dried over MgSO4, filtered and concentrated in vacuo to afford pure compounds 11-13. 5-(3,4-dimethoxyphenyl)-5-oxopentanoic acid (11) 92% yield. 1H NMR (300 MHz, CDCl3): delta = 7.51-7.54 (m, 1H), 7.47 (s, 1H), 6.82 (d, 1H, J = 9.1 Hz), 3.88 (s, 3H), 3.87 (s, 3H), 2.97 (t, 2H, J = 7.8 Hz), 2.44 (t, 2H, J = 7.8 Hz), 2.02 (m, 2H) ppm.

As the paragraph descriping shows that 108-55-4 is playing an increasingly important role.

Reference£º
Article; Guariento, Sara; Karawajczyk, Anna; Bull, James A.; Marchini, Gessica; Bielska, Martyna; Iwanowa, Xenia; Bruno, Olga; Fossa, Paola; Giordanetto, Fabrizio; Bioorganic and Medicinal Chemistry Letters; vol. 27; 1; (2017); p. 24 – 29;,
Tetrahydropyran – Wikipedia
Tetrahydropyran – an overview | ScienceDirect Topics

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

Into a 3L three-necked RB flask were charged [500ML] of methylene chloride, 250gr of aluminum chloride and 45gr of fluorobenzene (benzene content 300ppm) under nitrogen atmosphere. ‘The reaction mixture was cooled to [10C] and a solution of [LOOGR] of glutaric anhydride, 45gr of fluorobenzene (benzene content 300ppm) and [500ML] of methylene chloride was added slowly over a period of 3hrs between [10-15C.] The reaction mixture was maintained for another one hour at the same temperature. The reaction mixture was slowly poured onto a mixture of crushed ice (700gr) and conc. HCI [(300ML)] below [10C.] The reaction mass temperature was allowed to reach [25C] and methylene chloride distilled off from the reaction mixture below [50C.] After cooling the reaction mixture to [20C,] solids were filtered off and washed with [500ML] of water. The wet cake thus obtained was suspended in [250-300ML] of methylene chloride and filtered. The solid compound was dissolved in [600ML] of 4% sodium hydroxide, treated with [LOGR] of activated charcoal and filtered. The filtrate was acidified with conc. HCI and the precipitated acid was filtered. After washing the wet cake with [500ML] of water, it was dissolved in [500ML] of acetone. The acetone solution was slowly cooled to [15-20C] and the solid filtered, washed with chilled acetone (50ml) and dried at [50-70C] to get 122gr of white crystalline solid, m. p. [143C.] Purity by [HPLC] is 99.65%. Desfluoro impurity is less than 0.05%. Example 2 Preparation of [4- (4-FLUOROBENZOY) LBUTYRIC ACID] of formula-I using fluorobenzene (benzene content [500PPM)] with methylene chloride as solvent: Into a 3L three-necked RB flask were charged [500MI] of methylene chloride, 250gr of aluminum chloride and 45gr of fluorobenzene (benzene content 500ppm) under nitrogen atmosphere. The reaction mixture was cooled to [10C] and a solution of [LOOGR] of glutaric anhydride, 45gr of fluorobenzene (benzene content [500PPM)] and [500ML] of methylene chloride was added slowly over a period of 3hrs between [10-15C.] The reaction mixture was maintained for another one hour at the same temperature. The reaction mixture was slowly poured onto a mixture of crushed ice (700gr) and conc. [HCL] [(300ML)] below [10C.] The reaction mass temperature was allowed to reach [25C] and methylene chloride distilled off from the reaction mixture below [50C.] After cooling the reaction-mixture to [20OC-1 SOLIDS :] were filtered off and washed with [500ML] of water. The wet cake thus obtained was suspended in [250-300ML OF] methylene chloride and filtered. The solid compound was dissolved in [600ML] of [4%] sodium hydroxide, treated with [10GR] of activated charcoal and filtered. The filtrate pH was adjusted’to 1.0-2. 0 with conc. [HCL] and the precipitated acid of formula-I was filtered. After washing the wet cake with [500ML] of water, it was dissolved in [500ML] of acetone. The acetone solution was slowly cooled to [15-20C,] maintained for 2h, and the solid filtered, washed with chilled acetone [(50ML)] and dried at [50-70C] to get 120gr of white crystalline solid of [FORMULA-1,] m. p. 143-143. [5C.] Purity by [HPLC] is 99. [7%.] Desfluoro impurity is less than 0.05%. Example 3 Preparation of [4- (4-FLUOROBENZOY)] lbutyric acid of formula-I using fluorobenzene (benzene content 700ppm) with methylene chloride as solvent: Tnto a 3L three-necked RB flask were charged 500ml of methylene chloride, 250gr of aluminum chloride and 45gr of fluorobenzene (benzene content [700PPM)] under nitrogen atmosphere. The reaction mixture was cooled to [10C] and a solution of [LOOGR] of glutaric anhydride, 45gr of fluorobenzene (benzene content 700ppm) and [500ML] of methylene chloride was added slowly over a period of 3hrs between [10-15C.] The reaction mixture was maintained for another one hour at the same temperature. The reaction mixture was slowly poured onto a mixture of crushed ice (700gr) [AND CONC. HCI (300ML)] below [10C.] The reaction mass temperature was allowed to reach [25C] and methylene chloride distilled off from the reaction mixture below [50C.] After cooling the reaction mixture to [20C,] solids were filtered off and washed with [500ML] of water. The wet cake thus obtained was suspended in [250-300ML] of methylene chloride and filtered. The solid compound was dissolved in [600ML] of 4% sodium hydroxide, treated with [LOGR] of activated charcoal and filtered. The filtrate pH was adjusted to 1.0-2. 0 with conc. [HCL] and the precipitated acid of formula-I was filtered. After washing the wet cake with [500ML] of water, it was dissolved in 500ml of acetone. The acetone solution was slowly cooled to [15-20C,] maintained for 2h, and the solid filtered, washed with chilled acetone [(50ML)] and dried at [50-70C] to get 123gr of white crystalline solid [OF FORMULA-1,] m. p. [143C.] Purity by [HPLC] is 99.6%. Desfluoro impurity is less than 0.05%.

108-55-4 Dihydro-2H-pyran-2,6(3H)-dione 7940, aTetrahydropyrans compound, is more and more widely used in various.

Reference£º
Patent; Natco Pharma Limited; Venkaian Chowdary Nannapaneni; WO2003/104180; (2003); A1;,
Tetrahydropyran – Wikipedia
Tetrahydropyran – an overview | ScienceDirect Topics