[orgasynth]

dear members,
kindly suggest me the synthetic conditions for 1-naphthalene sulfonic acid
thanks

[AWK]

http://www.meta-synthesis.com/webbook/24_complexity/complexity3.html

[Will]

When sulfonating naphthalene, the kinetically favoured product is 1-naphtalene sulfonic acid, so you want to use a temperature lower than 100^oC (around 80^oC most websites say).

You can sulfonate with conc. H₂SO₄, but because the reaction is relatively slow it may be better to use oleum (SO₃ in H₂SO₄).

[saltyf]

Tetrahedron Letters  (2004),  45(35),  6607-6609 have a detailed description of the reaction condition