1-isopropylamino

Alkylation of 2-methylaminothiazole (204) with ROH in 85% sulfuric acid gives 2-methylimino-3-alkyl-4-thiazoIine (54). 2-Amino-4-rnethyl-thiazoie alkylated with an excess of isopropanol, however, gives 95% of 2-isopropylamino-4-methyl-5-isopropylthiazole (56). The same result is obtained with cyclohexanol (242). These results and those reported in Sections III.l.C and IV.l.E offer interesting new synthetic possibilities in thiazole chemistry. The reactive species in these alkylations is the conjugate acid of 2-aminothiazole. and the diversity of the products obtained suggests that three nucleophilic centers may be operative in this species. 

Fluproquazone (97) contains a 2-quinazolinone nucleus and is found to be an analgetic agent useful in mild to moderate pain. One of the preparations involves reaetion of 2-isopropylamino-4-methyl-4 -fluoro-benzophenone (96) with potassium cyanate in hot acetic acid [27],... 

Isopropylamino-3-methylaniline (275) and ethoxalyl chloride gave l-isopropyl-8-methyl-2,3(l//,47/)-quinoxalinedione (276) (EtPr N, PhMe, —78°C, 1 h then 0°C, 16 h then reflux, 24 h 45%) several analogs were made simUarly. ° ... 

Isopentyl-2(l//)-quinoxalinone 3-Isopropoxycarbonyl-6,7-dimethyl-2-quinoxalinecarboxylic acid 2-Isopropylamino-6-methyl-3-phenylquinoxaline... 

Thereafter, the filtrate was evaporated to dryness in vacuo and the residue was taken up in alcohol. The crystalline precipitate which separated out after some standing was separated by vacuum filtration and washed with alcohol. After recrystallization from 90% alcohol, 61 g (83.2% of theory) of l-(3,5-dihydroxyphenyl)-l-hydroxy-2-isopropylamino-ethane sulfate, MP 202° to 203°C, was obtained. 

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