• Title/Summary/Keyword: alkylation

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Synthesis of 4-(2-thiazolyloxy)phenylalkanoic Acids As An An-tiinflammatory Agent

  • Choi, Hong-Dae;Shin, Sang-Hoon;Son, Byeng-Wha
    • Archives of Pharmacal Research
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    • v.19 no.2
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    • pp.148-152
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    • 1996

  • The efficient synthesis of 4-(2-thiazolyloxy)phenylalkanoic acids (10a-c), which are a potent antiinflammatory agent, was achieved in 5-6 steps starting from isopropoxybenzene and methyl $\alpha-chloro-\alpha-(methylthio)acetate (1)$. The key intermediate (4) was prepared by Friedel-Crafts reaction of isopropoxybenzene with (1) followed by desulfurization and the removal of isopropyl protector. Methyl 4-hydroxyphenylalkanoates (6, 8) were similarly obtained from alkylation of (3) and deprotection.

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N-Alkylation of Primary Aromatic Amines Using Alkylhalide and Triethylamine (알킬할라이드와 Triethylamine을 이용한 일급 아로미틱 아민의 N-알킬레이션)

  • Kim, Ju-Hee;Park, Myung-Sook
    • YAKHAK HOEJI
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    • v.49 no.2
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    • pp.162-167
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    • 2005

  • Synthetic method for the selective N-monoalkylation of anilines using alkyl halides and triethylamine under room temperature was described. The corresponding N-alkyl anilines were obtained in good yields with minor quantities of dialkylated products. Anilines 2a-m and 3a-m were identified using NMR and IR. A series of 2a-m and 3a-m has been synthesized from aniline, toluidines, ethylanilines, aminoacetophenones, phenetidines. Formation of anilines was undertaken with dropping of alkylhalides at room temperature in methanol (or ethanol) for 3 hours~5 days. Selectivity on the monoalkylation was relatively high. Synthetic ratio of monoalkylated and dialkylated product was 94 : 6 in case of maximum monoalkylation.

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Selective Acyl and Alkylation of Monobenzoyl p-tert- Buty1calix[4]arene

  • 김종민;전종철;남계춘
    • Bulletin of the Korean Chemical Society
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    • v.18 no.4
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    • pp.409-415
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    • 1997

  • Several calixarene derivatives of 5,11,17,23-tetra-tert-butyl-25-(3,5-dinitrobenzoyloxy)-26,27,28-trihydroxycalix[4]arene 2 were synthesized by the reaction of 2 with several acyl and alkylating agents in the presence of base such as pyridine and K2CO3 in THF. Acylation of monobenzoylated p-tert-butylcalix[4]arene 2 yielded their corresponding 1,3-diacylated calix[4]arenes 3a-3g. On the other hand, alkylation of 2 produced a variety calix[4]arene derivatives such as 1,2- and 1,3-disubstituted calix[4]arenes 4a-4c, 4e-4f, or 1,2,4-trisubstituted calix[4]arene 4d. 1,2-Disubstituted calix[4]arenes are chiral. All derivatives exist as a cone conformation based on NMR studies.

  • https://doi.org/10.5012/bkcs.1997.18.4.409 인용 PDF

Synthesis of Novel Alkyl $\alpha$-Anilinophenylacetate Derivatives Using Hydrolysis of Hydantoin Ring and Its O-Alkylation

  • Park, Hae-Sun;Park, Myung-Sook;Choi, Hee-Jeon;Kwon, Soon-Kyoung
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.244.2-244.2
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    • 2003

  • For the development of new synthetic method for unnatural amino acid esters, alkyl ${\alpha}$-anilinophenylacetates were synthesized through base-catalyzed hydrolysis of 1,5-diphenylhydantoins in methanol and O-alkylation of sodium ${\alpha}$-anilinophenylacetate with alkyl halides in DMF. Even though hydrolysis of hydantoin ring was undertaken under about 30-40$^{\circ}C$ in methanol, the hydantoic acid sodium salt was continuously converted to the sodium ${\alpha}$-anilinophenylacetate. (omitted)

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First Total Synthesis of (-)-Antofine by Using Catalytic Phase Transfer Alkylation.

  • Lee, Jae-Kwang;Lee, Tae-Ho;Park, Hyeung-Geun;Kim, Deuk-Joon;Kim, Sang-Hee
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.183.3-183.3
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    • 2003

  • Phenanthroindolizidine alkaloid, (-)-antofine has attracted attention because of its extremely potent inhibition of cancer cell growth (Its $IC_50$ values have the low nanomolar range). The frist asymmetric total synthesis of (-)-antofine is described. An important feature of this synthesis is the creation of a stereogenic center by enantioselective alkylation using the phase transfer catalyst (PTC) and ring-closing metathesis (RCM) for pyrrolidine ring construction. This synthesis is efficient to allow the asymmetric preparation of other naturally occurring phenanthroindolizidine and phenanthroquinolizidine alkaloid.

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