ChemicalBook CAS DataBase List 5-Bromothiazole

5-Bromothiazole synthesis

4synthesis methods

Product Name:5-Bromothiazole
CAS Number:3034-55-7
Molecular formula:C3H2BrNS
Molecular Weight:164.02

5-Bromothiazole is a monobromothiazole, which can be prepared via treatment of 2,5-dibromothiazole with sodium ethoxide followed by hydrogenation over spongy nickel.

3034-22-8 Synthesis

3034-22-8
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3034-55-7
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Yield:-

Reaction Conditions:

Stage #1:5-bromo-2-aminothiazole with phosphoric acid;nitric acid;sodium nitrite in water at -5; for 1 h;
Stage #2: with hypophosphorous acid in water at 0 - 20;

Steps:

To a solution of 2-amino-5-bromothiazole (12.58g, 70mmol) in a mixture of phosphoric acid (106ml of an 86% solution in water), and cone, nitric acid (19.2ml) cooled at - 5⁰C was added over 45 mins a solution of sodium nitrite (7.59g, 1 lOmmol) in water (26ml). 30 After the addition was complete the mixture was stirred at -5⁰C for 15 mins, then hypophosphorous acid (38.8ml) added dropwise over 30 mins keeping the temperature below O⁰C. The mixture was stirred at O⁰C for 150 mins then allowed to warm to room temperature overnight. The mixture was poured into a solution of NaOH (85g) in water (400ml). 5N NaOH EPO solution added until the mixture reached neutrality, and the resulting mixture extracted with CH₂Cl₂ (3 x 200ml). Combined CH₂Cl₂ layers washed with sat. NaCl, dried over Na₂SO₄, filtered and evaporated. The residue was purified by MPLC on silica gel eluting with a gradient rising from 100% hexanes to 10% EtOAc in hexanes to give of the title compound. HNMR 5 (500 MHz, CDCl₃) δ: 8.78 (s, IH), 7.83 (s, IH).