PROCESSES FOR PREPARING 2-SUBSTITUTED HYDROXYIMINO-2-(5-AMINO-1,2,4-THIADIAZOL-3-YL)ACETIC OR TIS SALT

摘要

The title compds. (I) or its salts are prepd. by hydroly sis of (II), where R1 is substituteable lower alkyl, lower alkenyl, cycloalkyl or substd. five membered hetero ring contg. sulfur. Stir a soln. contg. water 268 mL, 2-cyanoacetamide 67.0g and sodium nitrite 66.1g in an ice bath for 3hrs add acetic acid 95.8g into the rxn. mixt. at 10-15 deg.C and then diethyl sulfate 147.5g after adjusting pH 8.5 with 4N NaOH 350 mL, restir for 1h at 40-50 deg.C, cool in ice bath, filter and wash with ice water to give 2-cyano-2-ethoxyiminoacetamide 70.0g.