✦ LIBER ✦

13C and 17O NMR study of methoxy groups in chlorinated Di- and trimethoxybenzenes

✍ Scribed by J. Knuutinen; E. Kolehmainen

Publisher: John Wiley and Sons
Year: 1990
Tongue: English
Weight: 275 KB
Volume: 28
Category: Article
ISSN: 0749-1581
DOI: 10.1002/mrc.1260280407

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

^13^C and ^17^O NMR data [chemical shifts and ^1^J(CH) values] for the methoxy groups in isomeric 1,2‐, 1,3‐ and 1,4‐dimethoxybenzenes, 1,2,3‐trimethoxybenzenes and most of their chlorinated derivatives and some related brominated compounds were measured for CDCl^3^ solutions. The ^17^O NMR chemical shifts show up to 60 ppm dispersion. Comparison between the compounds with and without adjacent chlorine atoms (2,6‐di‐ and 2,4,6‐tri‐substitution) also showed a clear methoxy carbon chemical shift change. The number and position of the chlorine atoms in the aromatic ring give small but observable effects on the ^17^O NMR chemical shifts of the methoxy group if it is coplanar with the aromatic plane. Similarly, the degree and nature of the substitution have a minor effect (about 1 Hz) on the ^1^J(CH) direct coupling values.

📜 SIMILAR VOLUMES

17O NMR study of chlorinated anisoles

✍ E. Kolehmainen; J. Knuutinen 📂 Article 📅 1988 🏛 John Wiley and Sons 🌐 English ⚖ 201 KB

## Acknowledgements The author thanks UMYMFOR (CONICET-FCEyN-UBA) and lic. Dario Doller for generous technical support, and the Universidad de Buenos Aires for financial support. l-Ethyl-9-(l'-ethyl-9'H-py~idof3,4-b]indol-3'-yl)pyrido(3,4-b)indole (22). Colourless plates from benzene-EtOH, m.p.

1H, 13C and 17O NMR study of substituted

1H, 13C and 17O NMR study of substituted nitropyridines

✍ Erkki Kolehmainen; Katri Laihia; Danuta Rasala; Ryszard Gawinecki 📂 Article 📅 1991 🏛 John Wiley and Sons 🌐 English ⚖ 492 KB 👁 1 views

## Abstract ^1^H, ^13^C and ^17^O NMR spectra for 22 substituted nitropyridines were measured and their ^1^H NMR spectra were analysed. The most significant variations in the NMR parameters are found for isomeric hydroxy derivatives, owing to the possibility of keto–enol tautomerism. The prevalence

NMR of enaminones. part 6—17O and 13C NM

NMR of enaminones. part 6—17O and 13C NMR study of tautomerization in Schiff bases

✍ Jin-Cong Zhuo 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 134 KB 👁 2 views

13C and 17O NMR spectra are reported for three series of Schi † bases : 2-(aminomethylene)cyclohexanones (1), salicylideneamines (2) and N-(2-hydroxy-1-naphthalenylmethylene)amines (3). The 13C and 17O NMR data show that Schi † bases 1 exist in ketoenamine form, 2 in enolimine form and 3 as an equil

1H, 13C and 17O NMR study of chlorovanil

1H, 13C and 17O NMR study of chlorovanillins and some related compounds

✍ Erkki Kolehmainen; Katri Laihia; Juha Knuutinen; Juha Hyötyläinen 📂 Article 📅 1992 🏛 John Wiley and Sons 🌐 English ⚖ 474 KB

## Abstract ^1^H, ^13^C and ^17^O NMR chemical shifts and ^__n__^__J__(H,H), ^1^__J__(C,H) and ^3^__J__(C‐6, H‐formyl) spin—spin coupling constants of chlorinated vanillins (3‐methoxy‐4‐hydroxybenzaldehydes) were determined. The variation in the long‐range ^4^__J__(H,H) value between the formyl pro

13C, 17O and 1H NMR study of the protona

13C, 17O and 1H NMR study of the protonation of acetone in water

✍ Lian-fang Shen; You-Ru Du; Qian-fen Shao; Shi-zhen Mao 📂 Article 📅 1987 🏛 John Wiley and Sons 🌐 English ⚖ 339 KB

The protonation of acetone in water for a wide range of compositions of the binary mixture was studied by multinuclear NMR spectroscopy. Formation constants (Ill and K2) and 13C, "0 and 'H chemical shifts of the 1: 1 and 1:2 complexes were evaluated. The correlation of the 'H chemical shift of uncom

17O NMR study of isomeric monochloro- an

17O NMR study of isomeric monochloro- and monohydroxy-benzaldehydes and chlorinated salicylaldehydes

✍ E. Kolehmainen; J. Knuu-Tinen 📂 Article 📅 1991 🏛 John Wiley and Sons 🌐 English ⚖ 178 KB

The 1 7 0 N M R chemical shifts of isomeric monochloro-and monohydroxybenzaldehydes and chlorinated salicylaldehydes were measured at 40°C for 0.25 M CDCI, solutions. The "0 N M R chemical shift of the carbonyl oxygen of the compounds studied varies from 506 to 573 ppm measured from external D,O. Th