Yield:98169-74-5 70.4 g (78%)

Reaction Conditions:

with chlorine in HOAc-H₂ O;

Steps:

38 Preparation of 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-2-sulfonyl chloride

EXAMPLE 38 Preparation of 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-2-sulfonyl chloride Chlorine was bubbled into a suspension of 99.0 g (0.366 mol) of 2-benzylthio-5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine in 700 ml of HOAc--H₂ O (1:1, v/v) cooled to -1° C. During the course of the addition the temperature of the reaction mixture was maintained below 5° C. After 2.5 hours the chlorine addition was ceased and the reaction mixture was filtered to collect a tan solid. The filtrate was diluted with H₂ O to separate an additional quantity of solid which was collected by filtration. The combined solid products were dried in vacuo to yield 70.4 g (78%) of crude sulfonyl chloride III (X=Z=Me, Y=H) as a tan solid. IR and ¹ H-NMR spectra confirmed the structure. Recrystallization from EtOAc produced an analytical sample as an off-white solid, m.p. 128.5°-130.5° C. Analysis: Calculated for C₇ H₇ ClN₄ O₂ S: C, 34.09; H, 2.86; N, 20.73; S, 13.00; Found: C, 34.34; H, 2.80; N, 22.64; S, 12.85.

References:

US4755212,1988,A