Synthesis of 2-naphthalenesulfonic acid (beta-naphthylsulfonic acid)

Preparation of 2-naphthalenesulfonic acid

Preparation of 2-naphthalenesulfonic acid (beta-naphthylsulfonic acid)

Preparation of 2-naphthalenesulfonic acid (beta-naphthylsulfonic acid)

67 ml of concentrated sulfuric acid (d=1.84) is warmed to 100° C in a round bottom flask, and with proper stirring 100 g of finely grounded naphthalene are gradually added. The reaction mixture is heated at 160-170° for 12 hours without condenser. After cooling, the sulfonation mixture is poured into 1 litre of water, heated to boiling, and the CaO is added until an alkaline reaction is obtained. The mixture is filtered and precipitated CaSO4 is boiled up with 1000 ml of distilled water and hot solution is filtered. The filtrates are combined and evaporated to a small bulk and allowed to cool to room temperature. After standing overnight the calcium salt of the 2-naphthalenesulfonic acid crystallizes out and is filtered. The residue is dissolved in hot water, and a solution of sodium carbonate added till a filtered portion gives no further precipitate with sodium carbonate. The precipitated calcium carbonate is filtered, and the sodium salt of 2-naphthalenesulfonic acid evaporated till crystals appears. After standing overnight the crystals are filtered off and the filtrate further evaporated in order to obtain a second crop. The yield of 2-naphthalenesulfonic acid sodium salt is 120-140 g which is converted to 2-naphthalenesulfonic acid by neutralizing with stereochemical amount of hydrochloric acid.

The Synthetic Dyestuffs and the Intermediate Products from which They are Derived, by J. C. Cain, 213, 1905


naphthalene-2-sulfonic acid



InChI Key


Canonical SMILES


MeSH Synonyms

naphthalene-2-sulfonic acid

Depositor-Supplied Synonyms

Naphthalene-2-sulfonic acid, 2-NAPHTHALENESULFONIC ACID, 120-18-3, beta-Naphthylsulfonic acid, 2-Naphthalene Sulfonic Acid, beta-Naphthalenesulfonic acid, 2-Naphthylsulfonic acid, Kyselina 2-naftalensulfonova, Naphthalene-2-sulphonic acid, UNII-O9S4K2S25E, O9S4K2S25E, CHEBI:44229, KVBGVZZKJNLNJU-UHFFFAOYSA-N, EINECS 204-375-3, Kyselina 2-naftalensulfonova [Czech], SBB061349, 2-Naphthalenesulfonic acid, monohydrate, BRN 1955756, AI3-18435, 2-Sulfonaphthalene, PubChem19963, 2-naphtalenesulfonic acid, 2-napthalenesulfonic acid, AC1L1QYN, AC1Q6WYB, 2-naphthalenesulphonic acid, SCHEMBL1556, DSSTox_CID_24788, DSSTox_RID_80477, .beta.-Naphthylsulfonic acid, DSSTox_GSID_44788, Dehscofix 918 (Salt/Mix), beta-naphthalene sulfonic acid, .beta.-Naphthalenesulfonic acid, 249548_ALDRICH, CHEMBL1234624, CTK0H6223, MolPort-000-146-053, Tox21_301657, ANW-17466, AR-1E4265, AKOS015897326, AC-2569, DB08254, RP26419, VZ33468, NCGC00256154-01, AJ-26896, AK157719, AN-13866, CAS-120-18-3, KB-79243, LS-94867, SC-26801, B0258, FT-0600019, N0437, ST24048785, ST50214421, V1968, C16202, EC 204-375-3, EC 268-860-1, Naphthalene-2-sulfonic acid hydrate (Salt/Mix), 2-Naphthalenesulfonic acid monohydrate (Salt/Mix), 4-11-00-00527 (Beilstein Handbook Reference), L022029, 3B4-1363, I09-0619, UNII-VZW67VII75 component KVBGVZZKJNLNJU-UHFFFAOYSA-N, 76530-12-6

Removed Synonyms

naphthalene-2-sulfonate, CID8420, 54257-18-0, 5573-17-1, Nas

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