2-[1-(Ethylsulfonyl)-3-azetidinylidene]acetonitrile

Under a nitrogen atmosphere, in a 3L three-necked bottle, diethyl cyanomethylphosphonate (212.5 g, 1.2 mol) and anhydrous THF (300 ml) were added and dissolved by stirring, and then the temperature of the system was lowered to _10 ~0°C, Under this condition, a solution of t_Bu0K (123.2 g, 1.12 mol) in THF (200 ml) was slowly added dropwise, and the temperature of the control system was maintained at -10 to 0°C. At this temperature, the reaction was effected for 3-4 hours.Then, a solution of Intermediate B (163.0 g, 1.0 mol) in THF (300 ml) was slowly added dropwise during the dropwise addition of the THF solution containing Intermediate B.The temperature of the reaction system was controlled to be -10 ~ 0°C. After the dropwise addition, the mixture was stirred at this temperature for 2-3 hours, then slowly raised to room temperature and allowed to react for 15-18 hours at room temperature.Then the reaction solution was adjusted to pH 3-4 with water (500 ml), saturated NaCl solution (500 ml), 0.5 HC HCl, and extracted with ethyl acetate (500 ml X 2).The organic layers were combined and dried to afford an off-white solid 127, 48 in 68.5percent yield.450 g of tetrahydrofuran was added to the 2 L reaction flask. 21.3 g (0.12 mol) of diethyl cyanomethyl phosphate, The system was cooled to 10 ° C, and 7.0 g (0.13 mol) of sodium methoxide was added under nitrogen atmosphere. After the addition, the system gradually warmed to 20 °C. Stir for 45 min. A solution of 16.3 g (0.1 mol) of compound 6 and 80 g of tetrahydrofuran was continuously added dropwise to the system. After 1 hour, the reaction was stirred at 30 ° C for 10 h, and the reaction of the central control material was almost complete. After the system was cooled to 10 ° C, 500 g of ethyl acetate and 300 g of saturated brine were added. After stirring for 5 min, the layers were separated. The aqueous layer was extracted with 300 g of EtOAc EtOAc. The organic layer was washed with 500 g of water. The organic layer is dry, Filtration and concentration of the filtrate gave the crude product of compound 7, The crude product was washed with a small amount of n-hexane and dried to give 16.6 g of Compound 7. Yield: 96.4percent, HPLC ≥ 98.0percent.N, N-Diisopropylethylamine (4.5 mL) was added into a reaction vessel containing acetonitrile (50 mL) and 3-(cyanomethylene)azetidine hydrochloride (1.5 g; Formula VII) at about 0°C to about 10°C. The reaction mixture was stirred for about 10 minutes. Ethanesulfonyl chloride (2.22 g) was added into the reaction mixture at about 0°C to about 5°C over about 5 minutes. The temperature of the reaction mixture was raised to about 20°C to about 25 °C, and then the reaction mixture was stirred for about 16 hours. On completion of the reaction, acetonitrile was recovered from the reaction mixture under reduced pressure at about 40°C to about 45°C to obtain an oily residue. Dichloromethane (50 mL) was added into the residue. The contents were washed with a saturated sodium chloride solution (30 mL), followed by complete recovery of dichloromethane under reduced pressure at about 40°C to obtain 2-(l-(ethylsulfonyl)azetidin-3- ylidene)acetonitrile . Yield: 98.59percentTo a solution of 2-(azetine-3-yl) methyl cyanide(2.8 g, 21.4 mmol) and DIPEA(8.3 g, 64.3 mmol) in dichloromethane(30 mL) was added dropwise ethanesulfonyl chloride(4.1 g, 32.1 mmol) at 0°C under the protection of nitrogen, and the temperature was kept below 2°C when dropping. Trifluoroacetic acid (2 mL) was added to a solution of tert-butyl 3-(cyanomethylene)azetidine-1-carboxylate (2) (250 mg, 1.29mmol) in dichloromethane (20 mL). The solution was stirred at room temperature for 5 h. Then the reaction mixture was concentrated under reduced pressure to dryness. The residue, which contains the crude desired deprotection product 3, was then suspended ina cetonitrile (20 mL) and cooled to 0 °C. N, N-Diisopropylethylamine (DIPEA) (1.12 mL, 6.44 mmol, 5 equiv.) was then slowly added while keeping the internal temperature below 5 °C. Then ethanesulfonyl chloride (EtSO2Cl) (0.184 mL, 1.94 mmol, 1.5 equiv.) was added over 1 h while keeping the internal temperature below 5 °C. The resulting reaction mixture was stirred overnight at room temperature and then concentrated under reduced pressure. The concentrated residue was then diluted with dichloromethane and was washed with aqueous sodium chloride solution. The aqueous phase was back-extracted with dichloromethane. The combined organic layers were dried over Na2SO4 and the residue was purified using a silica gel column to afford compound 4: Yield 192 mg (81percent); off-white solid; m.p. 58–60 °C; IR: 3294, 3066, 2978, 2222, 1702, 1321, 1142 cm–1. Anal. calcd for C7H10N2O2S: C, 45.15; H, 5.41; N, 15.04; found: C, 45.32; H, 5.35; N, 15.21percent. MS (m/z): 209 [M + Na]+; 1H NMR (300 MHz, CDCl3): δ 1.37 (m, J = 6.7 Hz, 3H), 3.04 (m, J = 7.4 Hz, 2H), 4.69 (t, J = 2.5 Hz, 2H), 4.77 (t, J = 2.8 Hz, 2H), 5.43 (t, J = 2.4 Hz, 1H); 13C NMR (75 MHz, DMSO-d6): δ 7.2, 42.6, 58.5, 58.9, 93.9, 114.9, 156.2, 168.6.Compound 2 (0.250g, 1.29mmol) dissolved in acetonitrile was slowly added dropwise trifluoroacetic acid (3ml).Stirred at room temperature for 4 hours gussets tracking.After completion of the reaction, the solvent spin dry, obtained was dissolved in acetonitrile and cooled to 0 deg.] C, was slowly added N, N- diisopropylethylamine (DIEA), maintaining the temperature not higher than 5 .Was slowly added compound 8 (0.184ml, 1.94mmol, 1.5equiv), at T Completion of the reaction followed by TLC, concentrated under reduced pressure, the crude product was diluted with dichloromethane, washed with brine, the aqueous phase was extracted with dichloromethane, the organic phase was concentrated, dried over anhydrous sodium sulfate, and purified by column chromatography to give 0.192g white solid with a yield of 81percent.A three-necked flask was charged with compound 2 (16.33 g, 100 mmol) Cyanoacetic acid (17.01 g, 200 mmol) And toluene (82 mL), After stirring, piperidine (17.03 g, 200 mmol) was added, Plus after warming to reflux reaction 16-24 hours, The reaction was quenched by cooling to room temperature and adding 0.5 mol / L dilute hydrochloric acid (326 mL). The reaction mixture was separated and extracted with ethyl acetate (163 mL) The organic phase was washed with saturated brine twice (163 mL) Dried over sodium sulfate and concentrated to give Compound 3 (15.08 g, 81percent) by column chromatography on petroleum ether ethyl acetate mixed solvent column chromatography.Three-necked flask was charged with triphenylphosphine acetonitrile (33.14 g, 110 mmol) and dichloromethane (96 mL)And then 1- (ethylsulfonyl) azepin-3-one (prepared from Example 3) was added and reacted at room temperature for 3 to 4 hours. The reaction was quenched by the addition of 240 mL of water. The aqueous phase was extracted three times with ethyl acetate (120 mL). The organic phase was washed with saturated brine (120 mL) and concentrated to recrystallize from isopropyl ether and petroleum ether to give 2- [1-(ethylsulfonyl)-3-azetidinylidene] acetonitrile(16.76 g, 4 steps yield 67percent).

Molecular Weight:186.23
XLogP3:-0.9
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:2
Exact Mass:186.04629874
Monoisotopic Mass:186.04629874
Topological Polar Surface Area:69.6
Heavy Atom Count:12
Complexity:333
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes