Naphthyl Isothiocyanate

Submitted by J. Cvmerman-Craig, M. Moyle, and R. A. White. Checked by N. J. Leonabd and F. H. Owens. 

In a 500-ml. round-bottomed flask fitted with a reflux condenser are placed 16.2 g. (0.08 mole) of dry a-naphthylthiourea (Note 1) and 180 ml. of redistilled chlorobenzene. The flask is heated at the reflux temperature by means of an electric heating mantle. Evolution of ammonia begins almost at once, and all of the solid dissolves after 30-45 minutes. The solution is maintained at reflux for 8 hours (Note 2) and then evaporated on a steam bath at water-pump pressure to remove all of the chlorobenzene. The residue crystallizes on cooling and is extracted with four 30-ml. portions of boUing hexane (Note 3). Removal of solvent from the combined hexane extracts affords pale yellow crystals of a -naphthyl isothiocyanate, m.p. 58-59°. The yield is 12.7-13.0 g. (86-88%). Recrystallization from hexane (9 ml. of hexane for 1 g. of solute) gives colorless needles, melting point unchanged (Note 4). 

The checkers found that a 24-hour heating period increased the yield of a-naphthyl isothiocyanate to 95%. 

A fifth extraction yields no further product. The residue insoluble in hexane was found by the submitters to consist of 1.3-1.9 g. of a mixture of equal parts of di-a-naphthylthiourea and a-naphthylthiourea, m.p. 178-181.  

The method is generally applicable to the preparation of aryl isothiocyanates. Using this procedure, the submitters have prepared the following isothiocyanates, with the yields and times of refluxing indicated phenyl, 44%, 8 hours o-chlorophenyl, 46, 8 -bromophenyl, 73, 8 j -biphenylyl, 49, 6 /3-naphthyl, 70, 10 9-phenanthryl, 70, 10 1-pyrenyl, 72, 10. 

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Determination of ethyleneamines in air can be accomplished by absorbing the amines on NITC (1-naphthyl isothiocyanate) treated XAD-2 resin, then desorbing the derivative from the treated tubes and quantifying the amount using high performance Hquid chromatography (hplc). Sensitivity is reported as 0.37 and 0.016 mg/m for EDA and DETA, respectively, pet sample (153,154). 

Naphthyl isothiocyanate [551-06-4] M 185.3, m 58-59". Crystd from hexane (Ig in 9 mL). White needles soluble in most organic solvents but is insoluble in H2O. It is absorbed through the skin and may cause dermatitis. [Org Synth Coll Vol IV 700 1963.]... 

AS8L C11H7NS 1-naphthyl isothiocyanate L66j BNCS l-SCNC10Hy MeOH 56 PY NaBr 0.23 brucine. 0.03 DME/SCE OLAO C=l,t=lt.O, h=58... 

AS85 ChH7NS 2-naphthyl isothiocyanate L66J CNCS 2-SCNCi0H7 MeOH 56 PY NaBr 0.005 brucine 0.01 DME/SCE OltAC C=l, t=l. 0, h=58... 

Naphthyl isothiocyanate yields crystalline 1-naphthylthioureas and is similarly applied. 

Hu, K., and M.E. Morris. 2004. Effects of benzyl-, phenethyl-, and alpha-naphthyl isothiocyanates on P-glycoprotein- and MRPl-mediated transport. J Pharm Sci 93 1901. 

Naphthylacetamide, 32, 94 a-Naphthylcyanamide, 31, 20 /3-Naphthyl ethyl ether, 32, 97 a-NAPHTHYL isothiocyanate, 36, 56 /3-Naphthyl isothiocyanate, 36, 57 -Naphthyl methyl ether, 32, 100 a-Naphthylphenylacetylene, 34, 43 a-Naphthylthiourea, 36, 56 Neophyl chloride, 32, 90 Nickel, dicyclopentadienyl-, 36, 35 Nicotinamide, 30, 3 33, 52 Nicotinic acid, 6-hydroxy-, 36, 44 Nocotinonitrile, 33, 52... 

Naphthyl isothiocyanate 635 1-Naphthylthiourea (16.16 g) is heated in chlorobenzene (180 ml) at 150° under reflux for 8 h, then the chlorobenzene is distilled off, first at 20 mm, then at 1 mm. The residue is extracted with hexane (four 30-ml portions), which leaves a mixture of 1-naphthylthiourea and di-l-naphthylthiourea (0.65 g each) undissolved. The hexane solutions are united and evaporated, leaving 1-naphthyl isothiocyanate (12.75 g, 86%), needles, m.p. 58-58.5°. 

Naphthyl 2-hydroxybenzoate 1-Naphthylhydroxylamine 1-Naphthyl Isothiocyanate A/-2-Naphthyl-2-naphthalenamlne... 

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