最常用的酸催化酯化催化----Fischer-Speier酯化催化

聚合底物的缩合底物比如说：

3,4-Diaminobenzoic acid (152 g, 1.0 mol) was stirred with ethanol (2000mL) in a Morton flask. Hydrogen chloride gas was passed through the stirredsuspension for about 2 h. As the gas was absorbed, the slurry became gel-likein character. Ethanol (500 ml.) was added to the reaction mixture to dispersethe gel. The reaction mixture was refluxed 24 h. The mixture was filtered andthe filtrate was evaporated to dryness in vacuo. The filter cake and thefiltrate residue were dissolved in water (9 L). Theaqueous solution was made basic by the addition of solid sodium carbonate. Theproduct precipitated from the basic solution. The material was filtered anddried to yield ethyl 3,4-diaminobenzoate (130 g, 72.14%)。

3 、氯化亚砜先为聚合底物的缩合底物比如说：

To a suspension of 6-chloropyridine-2-carboxylic acid (8.3 g, 0.0525mol) in dioxane (25 mL), thionyl chloride (9.4 mL, 0.13 mol) was added and theresulting mixture was stirred at 70℃for 4 h. The reaction mixture was concentrated invacuo and a mixture of dioxane (8.3 mL) and ethanol (16.6 mL) was added. Thereaction mixture was heated to 70℃for 2 h, triethylamine (8.3 mL), ethanol (4.1 mL) andwater (8.3 mL) were added and the reaction mixture was again concentrated. Theresidue was distributed between diethyl ether (28 mL) and water (18 mL) and thephases were separated. The aqueous layer was extracted with diethyl ether (30mL) and the combined organic layers were dried over MgSO 4 , filteredand evaporated in vacuo to afford 6-chloropyridine-2-carboxylic acid ethylester (8.82 g, 91%) as oil。

4 、乙酰氯先为聚合底物的缩合底物比如说：

Acetyl chloride (15.3 mmol) was added dropwise to ethanol (50 mL) at 0℃. After 30 min, the acid (7.69 mmol) was added and thereaction mixture was heated at reflux for 15 h. The reaction mixture wasconcentrated and the residue was partitioned between dichloromethane (20 mL)and saturated sodium bicarbonate (10 mL). The aqueous layer was furtherextracted with dichloromethane (20 mL ×2) and the combined organic layers were dried(magnesium sulfate) and concentrated to provide the ester in 94% yield as brown oil。

主要起关键先为用的应该是乙酰氯和丙酮底物生成的HCl。

5、 对甲苯磺酯先为聚合底物的缩合底物比如说：

对甲苯磺酯先为缩合聚合底物只比硫酯稍弱，仍是一个过氧化氢，其用量与运用于硫酯大于，其关键先为用相近，运用于对甲苯磺酯先为为缩合聚合底物主要是为了避免硫酯带给的焦化和其他副底物。

A 300-mL, one-necked,round-bottomed flask was equipped with a magnetic stirrer, Dean-Stark trap, and a reflux condenser. The flask was charged with 3.0 g (20 mmol) of L-(+)-tartaric acid, 6.5 g (60 mmol) of benzyl alcohol, 47.5 mg (0.25 mmol) of p-toluenesulfonic acid monohydrateand 40 mL of toluene. The mixture washeated under reflux in an oilbath (about 130℃) for 13 h r.During this period the theoretical amount of water (0.62 mL) was collected. Themixture was allowed to cool to ambient temperature, diluted with ether, and poured into 50 mL of aqueous, saturated sodium bicarbonate. Theorganic phase was separated and the aqueous phase was extracted twice with 20 mL of ether. The combinedorganic phases were dried over sodiumsulfate. The solvent was removed with a rotary evaporator, and the resulting crudeproduct was triturated with hexane-ether (20:1, 210 mL) to give white crystals of (−)-dibenzyl tartrate.The precipitate was collected by filtration and washed with hexane-ether (20:1). Thefiltrate was further concentrated to give a second crop. The total yield was 6.2 g (94%), mp 49–50 ℃

三、酯交换

【 J. Org. Chem. , 1991, 56, 5307-5311】

【 ACS Catal. , 2011, 1, 1178–1182】

特别文献资料

1. Fischer, E.; Speier, A. Ber. Dtsch. Chem. Ges. 1895, 28, 3252-3258.

2. Hardy, J. P.; Kerrin, S. L.; Manatt, S. L. J. Org. Chem. 1973, 38, 4196-4200.

3. Fujii, T.; Yoshifuji, S. Chem. Pharm. Bull. 1978, 26, 2253-2257.

4. Pcolinski, M. J.; O’Mathuna, D. P.; Doskotch, R. W. J. Nat. Prod. 1995, 58, 209-216.

5. Kai, T.; Sun, X.-L.; Tanaka, M.; Takayanagi, H.; Furuhata, K. Chem. Pharm. Bull. 1996, 44, 208-211.

6. Birney, D. M.; Starnes, S. J. Chem. Educ. 1996, 76, 1560-1561.

7. Cole, A. C.; Jensen, J. L.; Ntai, I.; Tran, K. L. T.; Weaver, K. J.; Forbes, D. C.; Davis, J. H., Jr. J. Am. Chem. Soc. 2002, 124, 5962-5963.

8. Li, J. in Name Reactions for Functional Group Transformations, Li, J. J., Ed., Wiley: Hoboken, NJ, 2007. pp 458-461.

9. Saavedra, H. M.; Thompson, C. M.; Hohman, J. N.; Crespi, V. H.; Weiss, P. S. J. Am. Chem. Soc. 2009, 131, 2252-2259.

参考资料

一、 Name Reactions （A Collection of Detailed Reaction Mechanisms）, Jie Jack Li, Fischer-Speier esterification，page 252.

二、Organic Chemistry Portal：

三、化学空间：

。

重庆男科医院哪家看的好
辽宁男科医院哪家专业
南京治白癜风哪个医院好
南京医院哪家男科医院好
北京白癜风医院哪里比较好