The Action of Grignard Reagents on 2-Methoxy-1-Naphthonitrile

Abstract

The replacement of a nuclear alkoxyl group by the action of a Grignard reagent appears to have been realized first by Haller and Schaffer (1), who prepared a compound believed to be 3,5-dimethoxy-4-butylphenyl isobutyl ketone by the interaction of isobutylmagnesium bromide and 3,4,5-trimethoxybenzonitrile (I). This result was confirmed later by Hurd and Winberg (2). Similar replacements were observed by Fuson and Speck, working with certain o-methoxyaryl mesityl ketones (3). Later Richtzenhain found that various Grignard reagents brought about replacement of 2-alkoxyl groups in 2,3-dialkoxybenzonitriles (II) (4, 5).

2,8′-Disubstituted-1,1′-Binaphthyls: A New Pattern in Chiral Ligands

“…To this end, boronic acid [26] 10 was prepared as the nucleophilic partner from 1-bromo-2-methoxynaphthalene (9) from the corresponding Grignard reagent [26±28] (Scheme 2) and borate ester. To this end, boronic acid [26] 10 was prepared as the nucleophilic partner from 1-bromo-2-methoxynaphthalene (9) from the corresponding Grignard reagent [26±28] (Scheme 2) and borate ester.…”

“…The optical rotations were measured in THF with an error of < AE 0.1. 1 1-Bromo-2-methoxynaphthalene (9): [26] A solution of bromine (12.9 mL, 0.25 mol) in acetic acid (100 mL) was added to a solution of 2-methoxynaphthalene (8: 39.5 g, 0.25 mol) in acetic acid (350 mL) over the period of 30 min. The 13 C NMR spectra were recorded on a 101 MHz instruments (FT mode) for solutions in CDCl 3 at 25 8C.…”

“…The 1 H NMR spectra were recorded on 400 MHz instruments (FT mode) for solutions in CDCl 3 at 25 8C with TMS as internal reference. 85 ± 86 8C (in accordance with the literature [26] ); 1 After stirring for 30 min, the mixture was cooled to room temperature and added by means of a cannula to a solution of (iPrO) 3 B (29 mL, 126 mmol, 1.5 equiv) in THF (40 mL) at À 78 8C. The individual protons and carbon atoms were assigned by using DEPT, COSY, NOESY, HSQC, and HMBC techniques.…”

Synthesis and structures of complexes with axially chiral isoquinolinyl-naphtholate ligands

“…Extraction with light petroleum, concentration and cooling to -25 • C yielded very small yellow crystals which were unsuitable for X-ray crystallography. The elemental analysis suggested the composition Ca(L H ) 2 (15). The 1 H and 13 C NMR spectra showed the absence of THF ligands; the data were incompatible with a dimeric structure analogous to the magnesium complex; the observation of only one set of t-butyl signals for the ligands suggests a monomeric structure as in the case of Zn(L H ) 2 (13).…”

“…14 However, the reported synthesis of 3 by bromination in acetic acid was rather unsatisfactory and furnished a mixture of 3 and the 8-bromo isomer 4 in a 1:3 ratio (Scheme 2), from which 3 can be separated either by fractional crystallisation from methanol or by flash chromatography in about 25% yield. 15 Replacing acetic acid by chloroform as solvent increased the yield to 45%. 14 However, following the method of Patwari et al, 16 bromination with pyridinium bromochromate in acetic acid at 60 • C for 1 h provided a 98:2 mixture of the two isomers from which 3 could be isolated in 94% yield by flash chromatography.…”