Reaksi Hammick

Reaksi Hammick, berasal dari nama penemunya Dalziel Hammick, adalah reaksi kimia dekarboksilasi termal asam α-pikolinat dengan keberadaan senyawa karbonil, membentuk 2-piridil-karbinol.^[1]^[2]^[3]

Dengan menggunakan p-simena sebagai pelarut, telah ditunjukkan bahwa ia akan meningkatkan rendemen reaksi.^[4]

Mekanisme

Seketika pemanasan asam α-pikolinat, ia akan berdekarboksilasi membentuk zwiterion (2). Dengan keberadaan elektrofil seperti aldehida, zwiterion akan bereaksi dengan karbonil. Setelah transfer proton, karbinol (4) yang diinginkan terbentuk.

The mechanism of the Hammick reaction

Referensi

^ Dyson, P.; Hammick, D. L. (1937). "362. Experiments on the mechanism of decarboxylation. Part I. Decomposition of quinaldinic and isoquinaldinic acids in the presence of compounds containing carbonyl groups". J. Chem. Soc.: 1724. doi:10.1039/jr9370001724.
^ Hammick, D. L.; Dyson, P. (1939). "172. The mechanism of decarboxylation. Part II. The production of cyanide-like ions from α-picolinic, quinaldinic, and isoquinaldinic acids". J. Chem. Soc.: 809. doi:10.1039/jr9390000809.
^ Brown, E. V.; Shambhu, M. B. (1971). "Hammick reaction of methoxypyridine-2-carboxylic acids with benzaldehyde. Preparation of methoxy-2-pyridyl phenyl ketones". J. Org. Chem. 36: 2002. doi:10.1021/jo00813a034.
^ Sperber, N.; Papa, D.; Schwenk, E.; Sherlock, M. (1949). "Pyridyl-Substituted Alkamine Ethers as Antihistaminic Agents". J. Am. Chem. Soc. 71: 887. doi:10.1021/ja01171a034.

[1] Dyson, P.; Hammick, D. L. (1937). "362. Experiments on the mechanism of decarboxylation. Part I. Decomposition of quinaldinic and isoquinaldinic acids in the presence of compounds containing carbonyl groups". J. Chem. Soc.: 1724. doi:10.1039/jr9370001724.

[2] Hammick, D. L.; Dyson, P. (1939). "172. The mechanism of decarboxylation. Part II. The production of cyanide-like ions from α-picolinic, quinaldinic, and isoquinaldinic acids". J. Chem. Soc.: 809. doi:10.1039/jr9390000809.

[3] Brown, E. V.; Shambhu, M. B. (1971). "Hammick reaction of methoxypyridine-2-carboxylic acids with benzaldehyde. Preparation of methoxy-2-pyridyl phenyl ketones". J. Org. Chem. 36: 2002. doi:10.1021/jo00813a034.

[4] Sperber, N.; Papa, D.; Schwenk, E.; Sherlock, M. (1949). "Pyridyl-Substituted Alkamine Ethers as Antihistaminic Agents". J. Am. Chem. Soc. 71: 887. doi:10.1021/ja01171a034.

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