NOTES J. Ory. Chem., Vol. 38, No. 22, i9'73 3949 upon standing. Recrystallization from ethyl acetate gave 0.42 g (3970) of 2-methylamino-1, 3, 4-thiadiazole (4a), mp 65'(1it. O mp 65- 66'). B. Ethyl Formate 4-Methylthiosemicarbazone (3, R= CHa; R'= C2Hb).-The above reaction was repeated but the period of heating was 1 hr. At this time, the reaction flask was cooled in an acetone-Dry Ice bath and a white, crystalline product was obtained. ...