Category: 681128-38-1

Synthetic Route of 681128-38-1, Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 681128-38-1, name is Ethyl 3,3-difluorocyclobutanecarboxylate, This compound has unique chemical properties. The synthetic route is as follows.

NaOH (10.7 g, 0.268 mol) was dissolved in MeOH (100 mL) and H2O(100 mL). Ester 23 (40.0 g, 0.244 mol) was added at r.t., and the resulting mixture was stirred at r.t. for 15 h, then evaporated in vacuo to half of the volume, acidified with concd aq HCl to pH 1, and extracted with CH2Cl2 (3 × 350 mL). The combined organic extracts were evaporated in vacuo.Yield: 32.4 g (98%); white solid; mp 49-52 C. 1H NMR (500 MHz, CDCl3): delta = 12.11 (br s, 1 H), 3.06-2.96 (m, 1 H), 2.94-2.79 (m, 4 H). 13C NMR (125 MHz, CDCl3): delta = 179.6, 118.0 (dd, J = 284, 271 Hz), 38.1(t, J = 24.8 Hz), 26.0 (dd, J = 14.0, 5.7 Hz). 19F NMR (376 MHz, CDCl3): delta = -84.5 (d, J = 194 Hz), -97.8 (d, J = 194Hz). GCMS (EI): m/z = 119 [M – OH]+, 97 [M – CO2H]+. Anal. Calcd for C5H6F2O2: C, 44.13; H, 4.44. Found: C, 43.86; H, 4.42.

The chemical industry reduces the impact on the environment during synthesis Ethyl 3,3-difluorocyclobutanecarboxylate. I believe this compound will play a more active role in future production and life.

Reference:
Article; Melnykov, Kostiantyn P.; Granat, Dmitriy S.; Volochnyuk, Dmitriy M.; Ryabukhin, Sergey V.; Grygorenko, Oleksandr O.; Synthesis; vol. 50; 24; (2018); p. 4949 – 4957;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Reference of 681128-38-1,Some common heterocyclic compound, 681128-38-1, name is Ethyl 3,3-difluorocyclobutanecarboxylate, molecular formula is C7H10F2O2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

A solution of the compound described in Preparation 42 (2.30 g, 14 mmol), in diethyl ether (14 ml_), was added to a suspension of lithium aluminium hydride (1.17 g, 30.8 mmol), in diethyl ether (70 ml_), cooled to -45 0C. This mixture was stirred at -45 0C for 1 hour, then warmed to -10 0C for 1 hour. It was then slowly warmed to room temperature and stirred for 15 hours, After which time it was cooled to 4 0C and quenched with sequential addition of water (1.2 ml_), 10% aqueous solution of sodium hydroxide (1.2 ml_) and finally water (3.6 ml_). Diethyl ether (50 ml_) was then added and the solution was allowed to stir for 90 minutes. The organic layer was separated and the aqueous phase was back extracted with diethyl ether (3 x 50 ml_). The combined organic layers were dried over magnesium sulphate, filtered, and concentrated under reduced pressure to give a 45% solution of the title compound in diethyl ether (1.56 g, 92%). 1H-NMR (400 MHz, CDCI3): delta 2.30 (m, 3H), 2.60 (m, 2H), 3.65 (m, 2H).

The synthetic route of 681128-38-1 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; PFIZER LIMITED; GIBSON, Karl Richard; GREEN, Martin Peter; UNDERWOOD, Toby James; WAKENHUT, Florian; WO2010/32200; (2010); A1;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 681128-38-1, name is Ethyl 3,3-difluorocyclobutanecarboxylate, This compound has unique chemical properties. The synthetic route is as follows., Formula: C7H10F2O2

Preparation 32: 4-(3-chloro-5-(3,3-difluorocyclobutyl)-4,5-dihydro-1H-pyrazol-1-yl)- 2-methylbenzonitrile; Step 1 : ethyl S-O.S-difluorocvclobutvDacrylate; To a solution of ethyl 3,3-difluorocyclobutanecarboxylate (1.94 g, 11.82 mmol) in dichloromethane (40 ml_) at -78C was added diisobutyl aluminum hydride (13 ml_ of a 1.0M solution in hexanes, 13.0 mmol). The reaction was stirred at -78C for 45 min. Saturated aqueous ammonium chloride (40 ml_) was added, and the resulting mixture stirred overnight at room temperature. The biphasic mixture was filtered through celite. The organic layer was dried over sodium sulfate, filtered and concentrated to give 3,3- difluorocyclobutanecarboxaldehyde which was used immediately without further purification. To a suspension of sodium hydride, 60 wt% dispersion in mineral oil (487 mg, 12 mmol) in tetrahydrofuran at 0C was added triethyl phosphonoacetate (2.4 mL, 12.0 mmol) dropwise. After addition was complete, the mixture was allowed to warm to room temperature, and stirred until the suspension cleared (~10 min.). 3,3- difluorocyclobutanecarboxaldehyde was added as a solution in tetrahydrofuran (10 mL). The resulting solution was stirred at room temperature 4 h. Diethyl ether (40 mL) was added, and the reaction was quenched by addition of saturated aqueous ammonium chloride (20 mL). The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by silica gel chromatography eluting with a gradient of 0%-5% ethyl acetate in heptane to yield ethyl 3-(3,3- difluorocyclobutyl)acrylate (498 mg, 22%) as a yellow oil. 1 H NMR ( 400 MHz,CHLOROFORM-d) delta ppm 1.30 (3 H, t, J=7.1 Hz), 2.49 (2 H, m), 2.83 (2 H, m), 2.94 (1 H, m), 4.21 (1 H, q, J=7.2 Hz), 5.85 (1 H, dd, J=15.5, 1.3 Hz), 7.00 (1 H, dd, J=15.5, 7.3 Hz).

Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 681128-38-1.

Reference:
Patent; PFIZER INC.; ARHANCET, Graciela Barbieri; CASIMIRO-GARCIA, Agustin; CHEN, Xiangyang; HEPWORTH, David; MEYERS, Marvin Jay; PIOTROWSKI, David Walter; RAHEJA, Raj Kumar; WO2010/116282; (2010); A1;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics