原乙酸三乙酯

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:45.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a 100 mL flask equipped with air stirrer and thermometer and distillation condensor were added malononitrile (9.1 g, 0.138 mol, triethyl orthoacetate (26.8 g, 0.165 mol) and glacial acidic acid (0.4 mL) sequentially, and the mixture was stirred and gently heated (90° C.) until the ethanol formed in the reaction began to distill off. When all the ethanol had distilled off, the reaction temperature was raised slowly from 90° C. to 140° C. for 30 min to ensure completion of the reaction. The reaction mixture was allowed to cool to 45° C. to solidify. The resulting solid mass was broken up under hexane (20 mL) and hexane was decanted off. The solid was washed with ethanol (50 mL) to afford a colorless crystal. The ethanol solution was concentrated and allowed to cool to room temperature. Then the crystal was filtered, washed with ethanol dried under vacuum (12.3 g, 65.9% yield). To a 100 mL flask equipped with air stirrer thermometer and distillation condensor formed in the reaction to distill off When all the ethanol had distilled off the reaction temperature was raised slowly from 90° C. to 140° C. for 30 min completion of the reaction hexane was decanted off The solid was washed with ethanol (50 mL) to afford a colorless crystal The ethanol solution was concentrated to cool to room temperature Then the crystal was filtered washed with ethanol dried under vacuum (12.3 g, 65.9% yield)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A solution of the allylic alcohol 22-2 (1.2 g, 6.1 mmol) in triethyl orthoacetate (50 mL) was treated with propionic acid (0.022 mL, 0.31 mmol) and refluxed for 2 h. The cooled mixture was treated with a solution of 1:1 sat. brine/1N HCl (150 mL), then extracted with CH2Cl2 (3×125 mL). The pooled organic extracts were washed with sat. NaHCO3, dried, filtered and evaporated. Chromatography on silica gel (EtOAc) afforded 22-3 as a yellow glass. refluxed for 2 h extracted with CH2Cl2 (3×125 mL) The pooled organic extracts were washed with sat. NaHCO3 dried filtered evaporated

反应条件: temp:170.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Into a flask equipped with a stirrer, a distilling column, a nitrogen inlet, a heating jacket, and a thermometer were charged 486 g of triethyl orthoacetate, 408 g of pentaerythritol, 300 g of diethylene glycol dimethyl ether, and 0.9 g of PTSA. The mixture was gradually heated to 170° C. over a period of 5 hours. During this time 490 g of distillate were obtained. The distillate contained mostly ethanol and small amounts of diethylene glycol dimethyl ether. The temperature was lowered to 100° C., and the remaining diethylene glycol dimethyl ether was distilled off under reduced pressure (30 mbar). The residue was subjected to vacuum distillation. The fraction having a boiling temperature of 126-130° C. at a pressure of 4 mbar yielded 426 g of oil. This oil solidified to a clear solid having a melting point of 99° C. and had the following structure Into a flask equipped with a stirrer During this time 490 g of distillate were obtained was lowered to 100° C. the remaining diethylene glycol dimethyl ether was distilled off under reduced pressure (30 mbar) The residue was subjected to vacuum distillation

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of 2.5 g (0.015 mole) of 4-hydrazino-2-methyl-6-methylthiopyrimidine and 50 ml of triethyl orthoacetate was heated at its reflux temperature for five days, and was then cooled. The solid was separated by filtration and recrystallized with treatment with decolorizing charcoal from first an ethyl acetate-hexane mixture, and then a benzene-hexane mixture to provide 3,5-dimethyl-7-methylthio-1,2,4-triazolo[4,3-c]pyrimidine, m.p. 201°-203° C. was heated at its reflux temperature for five days was then cooled The solid was separated by filtration recrystallized with treatment with decolorizing charcoal from first an ethyl acetate-hexane mixture

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Using the method of Example 19, 2-ethylthio-4-hydrazino-6-phenylpyrimidine was reacted with triethyl orthoacetate to provide 5-ethylthio-3-methyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine which was recrystallized from a 50/50 mixture of ethyl acetate/cyclohexanes to provide white crystals of 5-ethylthio-3-methyl-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine, m.p. 219.5°-220° C.

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of 6a (9.36 g, 27 mmol), triethyl orthoacetate (34.75 mL, 189 mmol) and propionic acid (0.2 mL, 2.7 mmol) was heated at 138° C. for 20 h with removal of ethanol. The reaction mixture was cooled and concentrated under vacuum, and the residue was purified by flash column chromatography over silica gel with hexane:EtOAc (19:1) as eluant to give 7a (8.77 g, 78%) as an oil; IR (neat) 1737, 1471 cm-1 ; 1H NMR (CDCl3) δ 0.01 (br s, 12 H, SiCH3), 0.85 (br s, 18 H, C(CH3)3), 1.21 (t, 3 H, CH3CH2), 2.42 (s, 2 H, CH2COEt), 3.61 (AB q, J=9.3 Hz, 4 H), 4.06 (q, 2 H, CH2CH3), 5.06 (m, 2 H, CH=CH2), 5.84 (dd, J=19.9, 11.3, 1 H, CH=CH2); 13C NMR (CDCl3) δ -5.58, 14.24, 18.23, 25.84, 36.81, 45.97, 59.84, 64.63, 114.47, 139.73, 171.87. Anal. Calcd for C21H44O4Si2 : C, 60.52; H, 10.64. Found: C, 60.46; H, 10.62. The reaction mixture was cooled concentrated under vacuum the residue was purified by flash column chromatography over silica gel with hexane:EtOAc (19:1) as eluant