Yes that they did but Goering and Hitler order development of it to stop. There was also another development of it called the He-274. The 274 was actually first flown by the French after they captured it in 1945.
Here are some stats on it:
He-274
Type: High Altitude Heavy Bomber
Origin: Ernst Heinkel AG (later assigned to SAUF, Suresnes, France)
Models: V1 and V2
Production: Two prototypes
First Flight: December 1945 by the French
Engine:
Daimler-Benz DB 603A-2 inverted turbocharged V12
Horsepower: 1,850hp
Number: 4
Dimensions:
Wing span: 44.20m (145 ft. 2¼ in.)
Wing Surface Area: N/A
Length: 23.80m (78 ft. 1¼ in.)
Height: 2.10m (6 ft. 10½ in.)
Stabilizer Span: N/A
Weights:
Empty: 21,300kg (46,964 lb.)
Loaded: 38,000kg (83,786 lb.)
Performance:
Maximum Speed (Sea Level): 267 mph
Maximum Speed (11,000m): 360 mph (580 kph)
Cruise Speed: N/A
Range: 4250km (2,640 miles)
Initial Climb: N/A
Endurance: N/A
Service Ceiling: 46,915 ft (14,300m)
Armament:
N/A
Avionics:
N/A
He-277
Type: Heavy Bomber, Recce and Anti-Shipping Aircraft
Origin: Ernst Heinkel AG
Models: V1 to V3, B-5, B-6 and B-7 Series
Production: N/A
First Flight: Late 1943
Engine:
B-5:
Daimler-Benz DB 603A inverted V12
Horsepower: 1,850hp
Number: 4
B-6:
Jumo 213F
Horsepower: 2,060hp
Number: 4
Dimensions:
Wing span (B-5): 31.44m (103 ft. 1¾ in.)
Wing span (B-6): 40.00m (131 ft. 2¾ in.)
Wing Surface Area: N/A
Length: 22.15m (72 ft. 8 in.)
Height: 6.66m (21 ft. 10½ in.)
Stabilizer Span: N/A
Weights:
Empty (B-5): 21,800kg (48,067 lb.)
Loaded (B-5): 44,490kg (98,096 lb.)
Performance:
Maximum Speed: 354 mph (570 kph)
Cruise Speed: N/A
Range (B-5): 6000km (3,728 miles)
Range (B-6): 7200km (4,474 miles)
Initial Climb: N/A
Endurance: N/A
Service Ceiling: N/A
Armament:
N/A
Avionics:
N/A