Synthesis, Characterization, and Antihypertensive Evaluation of Some Novel 2,2,8,8-Tetramethyl-2,3,7,8-tetrahydro-4,6-diamino-3,7-dihydroxy-6,7-epoxy-benzo-[1,2-b:5,4-b′]dipyran Derivatives

Table 2

Physical and spectral analysis of 2,2,8,8-tetramethyl-2,3,7,8-tetrahydro-4,6-diamino-3,7-dihydroxy-6,7-epoxy-benzo-[1,2-:5,4-] dipyran derivatives 7a–e.

Comp. code	R	Molecular formula		FTIR (cm^−1)	^1H NMR (ppm)	Mass (M + 1)
7a		C27H23O4N	3.1	3352.7 (O–H str), 2934.2 (Ali C–H str),; 1138.8 (C–N str), 1615 (C=C str)	δ7.16 (m, 12H),; δ2.15 (s, 4H),; δ1.30 (s, 12H)	382.5
7b		C21H30O4N2	3.3	3317.8 (O–H str), 2924.4 (Ali C–H str),; 1094.4 (C–N str),; 1229.8 (C–O str), 1611.1 (C=C str)	δ5.37 (d, 1H),; δ2.15 (s, 6H),; δ1.26 (s, 12H)	374.0
7c		C23H25Cl2O4N	2.7	3395.5 (O–H str), 2927.9 (Ali C–H str),; 1256.6 (C–O str), 1655.1 (C=C str),; 1094.6 (C–N)	δ7.41 (s, 1H),; δ6.37 (s, 1H),; δ4.03 (d, 4H),; δ1.50 (s, 4H); δ1.43 (s, 12H)	451.1
7d		C28H29O4N	3.3	3266.4 (O–H str), 2940.8 (Ali C–H str),; 1251.6 (C–O str), 1650.8 (C=C str),; 1029.1 (C–N)	δ7.43 (m, 22H),; δ2.29 (s, 6H),; δ1.20 (s, 12H)	444.0
7e		C20H29O4N	4.2	3427 (O–H str), 3020.7 (Ali C–H str),; 1216.4 (C–O str), 1562.7 (C=C str),; 1041.1 (C–N)	δ3.47 (m, 4H),; δ2.29 (s, 4H),; δ1.20 (s, 12H)	348.2