4H-Cyclopentathiazole, 2-chloro-5,6-dihydro- synthesis

Yield:-

Reaction Conditions:

with tert.-butylnitrite;copper(l) chloride in acetonitrile at 20 - 65; for 3 h;

Steps:

X.4

2-Amino-5,6-dihydro-4H-cyclopentathiazole (230 mg, 1.64 mmol) was added to a solution of cupric chloride (260 mg, 1.97 mmol) and ferf-butylnitrite (0.3 ml, 2.46 mmol) in MeCN (0.5 ml) and the resulting mixture was stirred for 2 h at room temperature, then at 65⁰C for 1 h. The reaction was filtered and the filtrate partitioned between water and EtOAc. The organic fraction was dried (MgSO₄), filtered and concentrated under reduced pressure to give the chloride (140 mg), which was used without further purification. MS: [M+H]⁺ = 160.

References:

WO2009/150240,2009,A1 Location in patent:Page/Page column 121