
TY  - JOUR
A1  - Collins, DJ 
A1  - Hughes, TC 
A1  - Johnson, WM 
T1  - Regiospecific Syntheses of the Monomethylated 3-Phenyldihydro-1,2,4-triazin-6(1H)-ones
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1996
VL  - 49
IS  - 4
SP  - 463
EP  - 468
KW  - 
UR  - https://doi.org/10.1071/CH9960463 
N2  - Unambiguous syntheses of four unreported monomethylated derivatives of 3-phenyldihydro-1,2,4-triazin-6(1H)-ones, namely, the 1-methyl (2), 2-methyl (3), 4-methyl (4) and the imidic O-methyl derivative (5), are described. Regioselectivity was achieved for the synthesis of (2) by addition of ethyl glycinate to the 1,3-dipolar nitrile imine derived from N- methylbenzohydrazonoyl bromide hydrobromide (8). The key step for the synthesis of (3) was addition of benzyl 3-methylcarbazate (14) to ethyl N-[ chloro (phenyl) methylene ] glycinate (15b). The 4-methyl compound (4) was prepared by cycloaddition of ethyl N-( thiobenzoyl ) sarcosinate (21) with hydrazine hydrate, and the O-methyl compound (5) was prepared by reaction of sodium methoxide with 6-chloro-3-phenyl-4,5-dihydro-1,2,4-triazine (23). 
ER  -

