Tetrahidrofuranil refers to compounds derived from pyrrolo [1,2] [1,2,4] triazine - F - 4 - Amine of formula (i) wherein R1 and R2 are each H or F R3 or R4 is o F is CN, alkyl (c1-c4), among others R6 R5 is Oh h, among others.Preferred compounds are (2R, 3S, 4R, 5S) - 5 - (4 - aminopirrolo 1.2 [- F] [1,2,4] - 7 - triazin 3,4-dihydroxy - il) - 2 - (hydroxymethyl) - carbonitrilo tetrahydrofuran-2-ylmethyl 2 (2R, 3R, 4R, 5S) - 5 - (4 - aminopirrolo 1.2 [- f] [1,2,4] triazin - 7 - yl) - 2 - etinilo - 4 - fluoro - 2 - (hydroxymethyl) tetrahydrofuran-3-yl ol among others.These compounds are useful for treating pneumovirinae virus Infections, including Infections by Respiratory syncytial virusSE REFIERE A COMPUESTOS DERIVADOS DE TETRAHIDROFURANIL-PIRROLO[1,2-f][1,2,4]TRIAZINA-4-AMINA DE FORMULA (I) DONDE R1 Y R2 SON CADA UNO H O F R3 ES OH O F R4 ES CN, ALQUILO(C1-C4), ENTRE OTROS R6 ES OH R5 ES H, ENTRE OTROS. SON COMPUESTOS PREFERIDOS: (2R,3S,4R,5S)-5-(4-AMINOPIRROLO[1,2-f][1,2,4]TRIAZIN-7-IL)-3,4-DIHIDROXI-2-(HIDROXIMETIL)TETRAHIDROFURAN-2-CARBONITRILO (2R,3R,4R,5S)-5-(4-AMINOPIRROLO[1,2-f][1,2,4]TRIAZIN-7-IL)-2-ETINILO-4-FLUORO-2-(HIDROXIMETIL)TETRAHIDROFURAN-3-OL ENTRE OTROS. DICHOS COMPUESTOS SON UTILES PARA TRATAR INFECCIONES POR EL VIRUS PNEUMOVIRINAE, QUE INCLUYE INFECCIONES POR EL VIRUS SINCITIAL RESPIRATORIO